UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

~~WASHINGTON~~Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 orOR 15(d) of ~~the~~

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): ~~October 28~~December 18, 2012

OPNET ~~Technologies~~TECHNOLOGIES, ~~Inc~~INC.

(Exact ~~Name~~name of ~~Registrant~~registrant as ~~Specified~~specified in ~~Charter~~its charter)

Delaware	000-30931	52-1483235
(State or Other Jurisdiction of Incorporation	(Commission File Number)	(IRS Employer Identification No.)
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)
7255 Woodmont Avenue, Bethesda, Maryland		20814
(Address of Principal Executive Offices)		(Zip Code)

~~Registrant’s~~7255 ~~telephone~~Woodmont ~~number,~~Avenue ~~including area code: (240) 497-3000~~

~~(Former Name or Former Address~~Bethesda, ifMD ~~Changed~~20814 ~~Since Last Report)~~

(Address of principal executive offices, including zip code)

(240) 497-3000

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

x¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

~~Item~~Introduction ~~1.01 Entry into a Material Definitive Agreement.~~

As previously reported, on October 28, 2012, Riverbed Technology, Inc. (“Riverbed”) entered into an Agreement and Plan of Merger (the “Merger Agreement”), by and among OPNET Technologies, Inc. (“OPNET”), Octagon Acquisition Corp., a wholly owned subsidiary of Riverbed (“Acquisition Sub”) and Riverbed, pursuant to which Acquisition Sub, on the terms and subject to the conditions thereof, commenced an exchange offer (the “Offer”) to acquire all of the outstanding shares of common stock, par value $0.001, of OPNET (“OPNET Common Stock”) in exchange for consideration, per share of OPNET Common Stock, comprised of: (i) $36.55, net to the seller in cash (the “Cash Consideration”); and (ii) 0.2774 of a share of Riverbed common stock, par value $0.0001 (the “Stock Consideration” and, together with the Cash Consideration, the “Offer Price”), without interest and subject to any tax withholding.

On ~~October~~December 2818, 2012, ~~the~~Acquisition ~~registrant,~~Sub and ~~OPNET~~certain ~~Technologies,~~of ~~Inc~~its affiliates announced the completion of the Offer. Also on December 18, a2012, ~~Delaware~~because ~~corporation~~Riverbed (“then owned more than 90% of the outstanding OPNET”) Common Stock, ~~entered~~in ~~into~~accordance anwith the Merger Agreement and ~~Plan~~as ofpermitted ~~Merger~~by applicable law, Acquisition Sub merged with and into OPNET (the “Merger ~~Agreement~~”). ~~with~~At ~~Riverbed~~the ~~Technology,~~effective ~~Inc.,~~time aof ~~Delaware~~the ~~corporation~~ Merger (the “~~Riverbed~~Effective Time”),: ~~and~~(i) OPNET ~~Octagon~~became ~~Acquisition~~the ~~Corp.,~~surviving acorporation ~~Delaware~~in ~~corporation~~the Merger and a wholly -owned subsidiary of Riverbed; and (~~“Acquisition Sub”~~ii). each ~~The~~outstanding ~~board~~share of ~~directors~~OPNET ofCommon ~~OPNET~~Stock ~~has~~(except ~~unanimously~~for: (iA) ~~determined that~~shares ~~the~~of ~~Merger~~OPNET ~~Agreement~~Common ~~and~~Stock ~~the~~held ~~transactions~~by ~~contemplated~~OPNET by(or ~~the~~in ~~Merger~~OPNET’s ~~Agreement~~treasury), ~~are~~Riverbed, ~~advisable~~Acquisition Sub or any other wholly-owned subsidiary of Riverbed, ~~fair~~which towere cancelled, retired and innow ~~the~~cease ~~best~~to ~~interests~~exist; and (B) shares of OPNET ~~and~~Common ~~its~~Stock held by OPNET stockholders who properly preserved their appraisal rights, ~~(ii~~if any, under Delaware law) ~~approved~~ ~~and~~were ~~declared~~converted ~~advisable~~into the ~~Merger~~right ~~Agreement,~~to receive the ~~Offer~~same consideration (as ~~defined~~ ~~below),~~ the ~~Merger~~Offer ~~(as~~Price ~~defined~~for ~~below)~~each ~~and~~share of OPNET Common Stock in the ~~transactions~~Offer, ~~contemplated~~subject ~~thereby~~to appraisal rights in accordance with ~~the~~Section 262 ~~requirements~~ of the Delaware ~~law~~General ~~and~~Corporation Law, as amended (~~iii~~the “DGCL”) ~~resolved~~. toFollowing ~~recommend~~the ~~that~~Effective Time, the ~~stockholders~~OPNET ofCommon ~~OPNET~~Stock ~~accept~~was delisted from the ~~Offer~~NASDAQ ~~and~~Global ~~tender~~Select ~~their~~Market ~~shares to~~and ~~Acquisition~~will ~~Sub~~be ~~pursuant~~deregistered tounder the ~~Offer~~Securities (Exchange Act of 1934, as ~~defined~~amended ~~below~~(the “Exchange Act”),. ~~and~~Following such deregistration, toOPNET will no longer file periodic reports with the ~~extent~~Securities ~~required~~and ~~under~~Exchange ~~applicable~~Commission ~~law,~~(the ~~adopt~~“SEC”) on account of the ~~Merger~~OPNET ~~Agreement~~Common Stock.

Pursuant to the Merger Agreement, Acquisition Sub will, on the terms and subject to the conditions thereof, commence an exchange offer (the “Offer”) to acquire all of the outstanding shares of common stock, par value $0.001, of OPNET (“OPNET Common Stock”) in exchange for consideration, per share of OPNET Common Stock, comprised of: (i)Item ~~$36~~1.~~55, net to the seller in cash (the “Cash Consideration”); and (ii) 0~~01.~~2774 of a share of Riverbed common stock, par value $0.0001 (the “Stock Consideration” and, together with the Cash Consideration, the “Offer Price”),~~ ~~without~~Entry ~~interest. Following consummation of the Offer, on the terms and subject to the conditions set forth in the Merger Agreement, Acquisition Sub will merge with and~~ into ~~OPNET with OPNET surviving as~~ a ~~wholly-owned~~Material ~~subsidiary~~Definitive ~~of Riverbed (the “Merger”)~~Agreement. Upon the Merger being effective, shares of OPNET Common Stock not tendered and accepted pursuant to the Offer (other than shares of OPNET Common Stock owned directly or indirectly by OPNET, Riverbed or Acquisition Sub, or any of their respective subsidiaries, or shares of OPNET Common Stock as to which appraisal rights have been perfected in accordance with applicable law), will be cancelled and converted into the right to receive the Offer Price. Upon consummation of the Merger: (i) OPNET’s outstanding options will be converted into equity awards of Riverbed on substantially equivalent terms; and (ii) OPNET’s outstanding restricted stock and restricted stock units will be assumed by Riverbed and converted into the right to receive the Offer Price on substantially equivalent terms.

~~Consummation of~~On ~~the~~December 18, ~~Offer~~2012, isin ~~subject~~connection towith ~~various conditions set forth in~~ the ~~Merger Agreement~~Offer, ~~including,~~Riverbed ~~among~~entered ~~others: (i) at least~~ into a ~~majority~~credit ofagreement ~~shares~~for ofa ~~OPNET~~$575,000,000 ~~Common~~senior ~~Stock~~secured ~~then~~term ~~outstanding~~loan facility (~~calculated~~the on“Senior aCredit ~~fully-diluted basis~~Facility”) ~~being~~with ~~tendered~~certain inlenders, ~~the Offer;~~Morgan ~~(ii) the~~Stanley ~~expiration~~Senior orFunding, ~~termination~~Inc., ofas ~~the~~administrative ~~applicable~~agent, ~~waiting~~Goldman ~~period~~Sachs ~~under~~Bank ~~the~~USA, ~~Hart-Scott-Rodino~~as ~~Antitrust~~syndication ~~Improvements~~agent, ~~Act~~Morgan Stanley & ofCo. ~~1976~~LLC, as ~~amended;~~collateral ~~(iii) the~~agent, ~~absence~~Bank of ~~any~~America, ~~Company~~N.A., ~~Material Adverse Effect (~~as ~~defined~~documentation inagent, ~~the~~Morgan ~~Merger Agreement);~~Stanley ~~(iv) the~~Senior ~~registration~~Funding, ~~statement~~Inc. ~~for~~and ~~Riverbed’s~~Goldman ~~common~~Sachs ~~stock~~Bank ~~issuable~~USA inas ~~connection~~joint ~~with~~lead ~~the~~arrangers ~~Offer~~ and ~~the~~joint ~~Merger~~bookrunners, ~~being declared effective by the Securities~~ and ~~Exchange~~Merrill ~~Commission~~Lynch, ~~(the “SEC”); and~~Pierce, ~~(v)~~Fenner ~~the~~& ~~receipt~~Smith byIncorporated, ~~Riverbed~~as ~~of sufficient proceeds to consummate the Offer~~arranger.

~~The~~In ~~Offer~~connection ~~will~~with ~~expire~~Riverbed’s atentering ~~midnight,~~into ~~New~~the ~~York~~credit agreement ~~time~~governing the Senior Credit Facility, on ~~the~~December 18, ~~20th~~2012, ~~business~~OPNET, ~~day~~upon ~~following~~becoming ~~the~~a ~~commencement~~wholly-owned ~~date~~subsidiary of ~~the Offer~~Riverbed, ~~unless~~entered ~~extended~~into ina ~~accordance~~Guarantee ~~with~~and ~~the~~Collateral ~~terms~~Agreement, ofdated ~~the~~December 18, ~~Offer~~2012, ~~and~~pursuant ~~the~~to ~~Merger~~which ~~Agreement~~OPNET agreed to guarantee, and ~~the~~grant ~~applicable~~a ~~rules~~security ~~and~~interest ~~regulations~~to secure, the obligations of Riverbed under the ~~SEC~~Senior Credit Facility.

InThe ~~the~~credit agreement ~~Merger~~governing ~~Agreement, OPNET has granted Acquisition Sub a “top-up” option to purchase OPNET Common Stock equal to~~ the ~~lesser of~~Senior ~~the:~~Credit ~~(i) number~~Facility ofcontains ~~shares~~certain ofcovenants ~~OPNET Common Stock~~ that, ~~when~~among ~~added~~other tothings ~~shares of OPNET Common Stock already purchased by Riverbed or Acquisition Sub pursuant to the Offer, would equal one share more than 90% of outstanding OPNET Common Stock on a fully-diluted basis; or~~ (~~ii) aggregate number of shares of OPNET Common Stock that OPNET is authorized to issue under its certificate of incorporation that are not issued~~ and ~~outstanding~~subject ~~at the time the option is exercised. The aggregate purchase price payable for the shares of OPNET Common Stock being purchased pursuant~~ to ~~the~~certain ~~top-up~~exceptions), ~~option~~restrict ~~shall be determined by multiplying~~ the ~~number~~ability of ~~such shares by the Offer Price (which~~OPNET, ~~for~~as ~~these purposes, shall be equal to: (~~a~~) the Cash~~ ~~Consideration;~~restricted ~~plus~~subsidiary ~~(b) the dollar amount determined by multiplying the Stock Consideration by the average~~ of ~~the closing sale prices of a share of~~ Riverbed, ~~common stock as reported on the Nasdaq Global Select Market for each of the 10 consecutive trading days prior~~ to: ~~the date on which the top-up option is exercised).~~

~~The~~• ~~Merger~~incur ~~Agreement~~additional contains customary representations and warranties and covenants by the parties, including, among other things, a “no-shop” restriction on the ability of OPNET to solicit third party proposals relating to alternative transactions or to provide information or enter into discussions in connection with alternative transactions, subject to certain limited exceptions to permit OPNET’s board of directors to comply with its fiduciary duties. The Merger Agreement also contains customary termination rights for each of Riverbed and OPNET. In addition, if the Merger Agreement is terminated under certain circumstances, OPNET will be required to pay Riverbed a termination fee of $37,500,000. If the Merger Agreement is terminated under other circumstances, Riverbed will be required to pay OPNET a termination fee of $25,000,000. indebtedness;

~~Tender~~• ~~and~~make ~~Support~~investments, ~~Agreements~~acquisitions, loans and advances;

~~Concurrently~~• ~~with~~engage the execution and delivery of the Merger Agreement, on October 28, 2012, Marc Cohen, OPNET’s Chief Executive Officer and Chairman of its Board of Directors, and Alain Cohen, OPNET’s President and Chief Technology Officer and a member of its Board of Directors, each entered into a tender and support agreement (the “Tender and Support Agreements”) with Riverbed and Acquisition Sub, pursuant to which each of them agreed, among other things, to (i) tender all of their shares of OPNET Common Stock in ~~the~~transactions ~~Offer; (ii) vote their shares of OPNET Common Stock for approval of the Merger; (iii) vote their shares of OPNET Common Stock against any alternative transaction~~ with ~~respect to OPNET, on the terms and subject to the conditions set forth therein~~affiliates; and (iv) vote their shares of OPNET Common Stock against any other action that is intended, or would reasonably be expected, to impede, interfere with, delay, postpone, discourage or adversely affect the Offer, Merger or other transactions contemplated thereby. Aproximately 7,437,772 shares of OPNET Common Stock (representing approximately 32.6% of the outstanding shares of OPNET Common Stock (on a fully-diluted basis)), are subject to the Tender and Support Agreements. The Tender and Support Agreements terminate in the event the Merger Agreement is terminated.

~~Additional~~• ~~Information~~sell, transfer or otherwise dispose of assets, including capital stock of subsidiaries;

~~The~~• ~~foregoing~~alter ~~descriptions of~~ the ~~Merger~~business ~~Agreement~~it and the Tender and Support Agreements are not complete and are qualified in their entirety by reference to the Merger Agreement, which is attached as Exhibit 2.1 to this report and incorporated herein by reference and the form of Tender and Support Agreement, which is attached as Exhibit 2.2 to this report and incorporated herein by reference. conducts;

~~The~~2 Merger Agreement and the Tender and Support Agreements, and the foregoing descriptions of each agreement, have been included to provide investors and stockholders with information regarding the terms of each agreement. They are not intended to provide any other factual information about OPNET. The representations, warranties and covenants contained in each agreement were made only as of specified dates for the purposes of such agreements, were solely for the benefit of the parties to such agreements and may be subject to qualifications and limitations agreed upon by such parties. In particular, in reviewing the representations, warranties and covenants contained in each agreement and discussed in the foregoing descriptions, it is important to bear in mind that such representations, warranties and covenants were negotiated with the principal purpose of allocating risk between the parties, rather than establishing matters as facts. Such representations, warranties and covenants may also be subject to a contractual standard of materiality different from those generally applicable to stockholders and reports and documents filed with the SEC. Investors are not third-party beneficiaries under the Merger Agreement or the Tender and Support Agreements. Accordingly, investors and stockholders should not rely on such representations, warranties and covenants as characterizations of the actual state of facts or circumstances described therein. Information concerning the subject matter of such representations, warranties and covenants may change after the date of the agreements, which subsequent information may or may not be fully reflected in the parties’ public disclosures.

~~Item~~• ~~2.02.~~consolidate, ~~Results~~merge, ofliquidate ~~Operations~~or ~~and Financial Condition~~dissolve;

On• ~~October 29,~~grant 2012, OPNET announced its financial results for its second fiscal quarter ended September 30, 2012. The full text of the press release issued in connection with the announcement is attached as Exhibit 99.1 to this Current Report on Form 8-K. liens;

~~The~~• ~~information~~effect incertain ~~Item 2.02~~amendments of this Current Report on Form 8-K and the corresponding Exhibit 99.1 attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to ~~the liabilities~~organizational ofdocuments; that section, nor shall they be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Exchange Act, except as expressly set forth by specific reference in such a filing. and

~~Item~~• ~~8.01~~make ~~Other~~prepayments ~~Events~~on certain subordinated debt.

~~On October 29,~~In ~~2012,~~addition ~~OPNET~~to ~~and Riverbed issued a joint press release announcing~~ the ~~execution~~foregoing ofnegative ~~the~~covenants, ~~Merger Agreement. The full text of~~ the ~~press~~credit ~~release~~documents ~~issued~~governing ~~in connection with~~ the ~~announcement~~Senior isCredit ~~attached~~Facility asalso ~~Exhibit~~contain ~~99.2~~certain tocustomary ~~this~~representations ~~Current~~and ~~Report on~~warranties, ~~Form~~affirmative ~~8-K~~covenants and isevents of ~~hereby incorporated by reference~~default.

Item 9 2.0103. Creation of a Direct Financial ~~Statements~~Obligation ~~and~~or ~~Exhibits~~an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth under Item 1.01 is incorporated by reference herein.

Item 3.01. Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

On December 18, 2012, in connection with the Merger, OPNET notified the NASDAQ Stock Market LLC (“Nasdaq”) of its intent to remove its OPNET Common Stock from listing on the NASDAQ Global Select Market and requested that Nasdaq file a Notification of Removal from Listing and/or Registration on Form 25 with the SEC to delist and deregister the OPNET Common Stock, which Nasdaq filed on such date. OPNET intends to file with the SEC a Form 15 under the Exchange Act, requesting the deregistration of the OPNET Common Stock and the suspension of OPNET’s reporting obligations under Sections 13 and 15(d) of the Exchange Act.

Item 3.02. Unregistered Sale of Equity Securities.

As contemplated by the Merger Agreement, on December 18, 2012, Acquisition Sub exercised its top-up option (the “Top-Up Option”) to purchase additional OPNET Common Stock, and OPNET issued 11,396,173 shares of OPNET Common Stock (the “Top-Up Shares”) to Acquisition Sub, at a price of $41.53 per Top-Up Share. Acquisition Sub purchased the Top-Up Shares by: (i) paying in cash, by wire transfer of immediately available funds, an amount equal to the aggregate par value of the Top-Up Shares; and (ii) executing and delivering to OPNET a full recourse promissory note having a principal amount equal to the aggregate purchase price pursuant to the Top-Up Option less the amount paid in cash pursuant to the preceding clause “(i).” The Top-Up Shares, when added to the number of OPNET Common Stock directly or indirectly owned by Riverbed and Acquisition Sub at the time of exercise of the Top-Up Option, represented more than 90% of the OPNET Common Stock outstanding immediately after the issuance of the Top-Up Shares, which permitted Acquisition Sub to effect the Merger under applicable Delaware law. The Top-Up Shares were issued without registration under the Securities Act of 1933, as amended (the “Securities Act”), in reliance upon an exemption from registration pursuant to Section 4(2) of the Securities Act, as a transaction by an issuer not involving a public offering.

Item 3.03. Material Modification to Rights of Security Holders.

At the Effective Time, each outstanding share of OPNET Common Stock (except for: (A) shares of OPNET Common Stock held by OPNET (or in OPNET’s treasury), Riverbed, Acquisition Sub or any other wholly-owned subsidiary of Riverbed, which were cancelled, retired and now cease to exist; and (B) shares of OPNET Common Stock held by OPNET stockholders who properly preserved their appraisal rights, if any, under Delaware law) were converted into the right to receive the same consideration as the Offer Price for each share of OPNET Common Stock, subject to appraisal rights in accordance with Section 262 of the DGCL.

Item 5.01. Changes in Control of Registrant.

As a result of the acceptance of OPNET Common Stock in the Offer on December 18, 2012, a change of control of OPNET occurred. Upon the effectiveness of the Merger, OPNET became a direct wholly

owned subsidiary of Riverbed. The disclosure under Item 3.01 is incorporated herein by reference. The total amount of the cash consideration payable in connection with the change of control transaction was approximately $850,000,000. Riverbed funded the Offer and the Merger through existing cash and borrowings under the Senior Credit Facility described in Item 1.01 of this Current Report on Form 8-K.

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

In connection with the Merger and as contemplated by the Merger Agreement, each member of OPNET’s board of directors prior to the Merger voluntarily resigned from OPNET’s board of directors effective as of the Effective Time. On December 18, 2012, each of Jerry M. Kennelly and Randy S. Gottfried became the sole members of OPNET’s board of directors following the Effective Time.

In connection with the Merger and as contemplated by the Merger Agreement, each executive officer of OPNET prior to the Merger voluntarily resigned from his or her position as an executive officer at OPNET effective as of the Effective Time. On December 18, 2012, Jerry M. Kennelly was appointed Chief Executive Officer, President and Secretary of OPNET, Randy S. Gottfried was appointed Chief Financial Officer, Chief Operating Officer and Treasurer of OPNET, and Brett A. Nissenberg was appointed Senior Vice President and General Counsel of OPNET.

Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change of Fiscal Year.

Pursuant to the Merger Agreement, following the Effective Time, OPNET’s amended and restated certificate of incorporation in effect immediately prior to the Effective Time was amended and restated (the “Amended and Restated Charter”) to be in the form of the certificate of incorporation of Acquisition Sub. In addition, following the Effective Time, OPNET’s amended and restated bylaws in effect immediately prior to the Effective Time were amended and restated (the “Amended and Restated Bylaws”) to be in the form of the bylaws of Acquisition Sub.

Copies of the Amended and Restated Charter and the Amended and Restated Bylaws are filed as Exhibits 3.1 and 3.2 to this Current Report on Form 8-K and are incorporated herein by reference.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

2.1		Agreement and Plan of Merger, dated as of October 28, 2012, by and among OPNET Technologies, Inc., Riverbed Technology, Inc. and Octagon Acquisition Corp.*
Exhibit No.		Exhibit
2.2		Form of Tender and Support Agreement, dated October 28, 2012, by and among Riverbed Technology, Inc., Octagon Acquisition Corp. and certain stockholders of OPNET Technologies, Inc.
3.1		Amended and Restated Certificate of Incorporation of OPNET Technologies, Inc.
99.1		Press Release dated October 29, 2012 regarding financial results of OPNET Technologies, Inc. (1)
3.2		Amended and Restated Bylaws of OPNET Technologies, Inc.
99.2		Joint Press Release dated October 29, 2012 of Riverbed Technology, Inc. of OPNET Technologies, Inc.

*4 Schedules and certain exhibits omitted pursuant to Item 601(b)(2) of Regulation S-K. OPNET agrees to furnish supplementally a copy of such schedules or exhibits, or any section thereof, to the SEC upon request.

(1) This exhibit relating to Item 2.02 shall be deemed to be furnished, and not filed.

Important Information and Where To Find It

The exchange offer for the outstanding common stock of OPNET referred to in this communication has not yet commenced. This announcement is neither an offer to purchase nor a solicitation of an offer to sell shares of OPNET. OPNET stockholders are urged to read the relevant exchange offer documents when they become available because they will contain important information that stockholders should consider before making any decision regarding tendering their shares. At the time the offer is commenced, Riverbed will file exchange offer materials with the U.S. Securities and Exchange Commission and OPNET will file a Solicitation/Recommendation Statement with respect to the offer. The exchange offer materials (including a Prospectus and certain other offer documents) and the Solicitation/Recommendation Statement will contain important information, which should be read carefully before any decision is made with respect to the exchange offer. The Prospectus and certain other offer documents, as well as the Solicitation/Recommendation Statement, will be made available to all shareholders of OPNET at no expense to them. The exchange offer materials and the Solicitation/Recommendation Statement will be made available for free at the Securities and Exchange Commission’s web site at www.sec.gov. Free copies of the Offer to Purchase, the related Letter of Transmittal and certain other offering documents will be made available by Riverbed by mail to Riverbed Technology, Inc., 199 Fremont Street, San Francisco, California, 94105, attention: Investor Relations, and free copies of the Solicitation/Recommendation Statement will be made available by OPNET by mail to OPNET Technologies, Inc., 7255 Woodmont Avenue, Bethesda, Maryland 20814-7900, attention: Investor Relations.

Interests of Certain Persons in the Offer and the Merger

Riverbed will be, and certain other persons may be, soliciting OPNET stockholders to tender their shares in the exchange offer. The directors and executive officers of Riverbed and the directors and executive officers of OPNET may be deemed to be participants in Riverbed’s solicitation of OPNET’s stockholders to tender their shares in the exchange offer.

Investors and shareholders may obtain more detailed information regarding the names, affiliations and interests of the directors and officers of Riverbed and OPNET in the exchange offer by reading the Prospectus and certain other offer documents, as well as the Solicitation/Recommendation Statement, when they become available.

Safe Harbor for Forward-Looking Statements

Statements in this report that relate to future results and events are forward-looking statements based on OPNET’s current expectations regarding the Offer and other transactions contemplated by the Merger Agreement. Actual results and events in future periods may differ materially from those expressed or implied by these forward-looking statements because of a number of risks, uncertainties and other factors. There can be no assurances that a transaction will be consummated. Other risks, uncertainties and assumptions include the risk that OPNET may not satisfy one or more closing conditions, including because a material adverse event outside the control of OPNET occurs; that the Merger Agreement may be terminated; the impact of the current economic environment; risks related to OPNET’s ongoing business; and other risks that are described in OPNET’s Annual Report on Form 10-K for the fiscal year ended March 31, 2012, as filed with the Securities and Exchange Commission on June 8, 2012, as updated from time to time in subsequent SEC filings. OPNET undertakes no obligation to update these forward-looking statements except to the extent otherwise required by law.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the ~~Registrant~~registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	OPNET TECHNOLOGIES, INC.
Date: December 18, 2012		OPNET Technologies, Inc.
Date: October 29, 2012	By:	/s/ MEL WESLEY
	By:	/s/ Brett A. Nissenberg
		Mel Wesley
		Brett A. Nissenberg
		Chief Financial Officer
		Senior Vice President and General Counsel

~~EXHIBIT~~Exhibit ~~INDEX~~Index

ExhibitNo.		Description
Exhibit No.		Exhibit
2.1		Agreement and Plan of Merger, dated as of October 28, 2012, by and among OPNET Technologies, Inc., Riverbed Technology, Inc. and Octagon Acquisition Corp.*
3.1		Amended and Restated Certificate of Incorporation of OPNET Technologies, Inc.
2.2		Form of Tender and Support Agreement, dated October 28, 2012, by and among Riverbed Technology, Inc., Octagon Acquisition Corp. and certain stockholders of OPNET Technologies, Inc.
3.2		Amended and Restated Bylaws of OPNET Technologies, Inc.
99.1		Press Release dated October 29, 2012 regarding financial results of OPNET Technologies, Inc. (1)
99.2		Joint Press Release dated October 29, 2012 of Riverbed Technology, Inc. of OPNET Technologies, Inc.

* Schedules and certain exhibits omitted pursuant to Item 601(b)(2) of Regulation S-K. OPNET agrees to furnish supplementally a copy of such schedules or exhibits, or any section thereof, to the SEC upon request.

(1) This exhibit relating to Item 2.02 shall be deemed to be furnished, and not filed.

Filing Compare · OPNET TECHNOLOGIES INC