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                                                                    EXHIBIT 99.6

                                 RADIATA, INC.
                             STOCK OPTION AGREEMENT
                        UNDER THE 1999 STOCK OPTION PLAN

        THIS AGREEMENT is made effective as of ___ day of _______, 200__ (the
"GRANT DATE" which is the date the Option referred to herein was authorized for
granting by the Administrator of the Company's Option Plan), between Radiata,
Inc., a Delaware corporation (the "COMPANY"), and the undersigned Optionee.

        THE PARTIES AGREE AS FOLLOWS:

1.      Option Grant. Subject to all of the terms and conditions of this
        Agreement and of the Company's 1999 Stock Option Plan (the "OPTION
        PLAN"), Optionee will have an option (the "OPTION") to purchase the
        number of shares of the Company's common stock (the "SHARES"), for an
        exercise price per share (the "OPTION PRICE") and based upon the Vesting
        Start Date set forth below and an Expiration Date of the tenth
        anniversary of the Grant Date (subject to earlier termination as
        provided in the Option Plan) as set forth below:

            NUMBER OF SHARES
               SUBJECT TO THE OPTION:       ________
            OPTION PRICE PER SHARE:         $_______
            VESTING START DATE:             _______, 200__

        This Option will not be treated as an Incentive Stock Option ("ISO")
within the meaning of Section 422 of the Internal Revenue Code of 1986, as
amended.

2.      Vesting and Exercise.

        (a)     Vesting. Initially, the entire Option will be "Unvested" within
                the meaning of the Option Plan; portions of the Option will
                become "Vested" within the meaning of the Option Plan on the
                following schedule:

                (1)     twenty-five percent (25%) of the Shares subject to the
                        Option shall become Vested as of the first anniversary
                        of the Vesting Start Date; and

                (2)     the remaining seventy-five percent (75%) of the Shares
                        subject to the Option shall become Vested monthly
                        ratably (approximately __________ shares per month) on a
                        cumulative basis over the 36 month period commencing on
                        the first anniversary of the Vesting Start Date, subject
                        to the condition that Optionee does not suffer a Loss of
                        Eligibility Status prior to each such vesting date.

        (b)     Exercise of the Option. Optionee may exercise the Option, in
                whole or in part, at any time provided that those Option Shares
                acquired by Optionee with respect to that portion of the Option
                which is then an Unvested Option will be "Unvested Shares"
                (within the meaning of section 5(c)(viii) of the Option Plan)
                that are subject to the Company's repurchase right as set forth
                in section 6(c) of the Option Plan, until such Shares become
                "Vested Shares" on the same schedule of Vesting dates as is set
                forth in section 2(a) above (and also subject to the condition
                that


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                Optionee does not suffer a Loss of Eligibility Status prior to
                each such Vesting date).

        (c)     Limitation on Right of Repurchase. The Company's right of
                repurchase under Section 6.8(c) of the Option Plan shall be
                limited to the repurchase of Unvested Shares.

        (d)     Minimum Number of Shares. Any exercise of the Option must be for
                at least one hundred (100) Shares (without regard to adjustments
                to the number of Shares subject to the Option pursuant to
                section 8 of the Option Plan) or, if less, all of the remaining
                Shares subject to the Option.

        (e)     Notice of Exercise. Optionee or Optionee's representative may
                exercise the Option by giving written notice to the Company
                pursuant to section 6.5(a) of the Option Plan using the
                specified form of notice of exercise attached to this Agreement
                as Exhibit A. The notice will be signed by the person or persons
                exercising the Option. In the event that the Option is being
                exercised by the representative of Optionee, the notice will be
                accompanied by proof reasonably satisfactory to the Company of
                the representative's right to exercise the Option. Payment of
                the Option Price will accompany the notice and will be in any of
                the following forms acceptable to the Company: (i) cash or a
                check made payable to the Company; or (ii) by the delivery of
                one or more certificate(s) representing shares of the Company
                with a Fair Market Value on the date of exercise equal to the
                Option Price, together with a stock power executed in blank.

        (f)     Withholding Taxes. To the extent required by applicable federal,
                state, local or foreign law, and as a condition to the Company's
                obligation to issue any Shares upon the exercise of the Option
                in full or in part, Optionee will make arrangements reasonably
                satisfactory to the Company for the payment of any withholding
                tax obligations that arise by reason of such exercise.

        (g)     Issuance of Option Shares. Subject to the provisions of the
                Option Plan, after receiving a proper notice of exercise and
                payment of the applicable Option Price and withholding taxes,
                the Company will cause to be issued a certificate or
                certificates for the Option Shares as to which the Option has
                been exercised, registered in the name of the person rightfully
                exercising the Option. The Company will cause such certificate
                or certificates to be delivered to such person.

3.      Representations and Warranties of Optionee. Optionee hereby represents
        and warrants that: (a) Optionee is acquiring the Option granted hereby,
        and will acquire any Shares obtained upon exercise of the Option, for
        investment purposes only, for Optionee's own account, and with no view
        to the distribution thereof; (b) Optionee understands that the Option
        and the Shares that may be acquired by exercising the Option ("OPTION
        SHARES") have not been registered under the Securities Act of 1933, as
        amended (the "1933 ACT") and that the Option and the Option Shares are
        not freely tradeable and must be held indefinitely unless they are
        either registered under the 1933 Act or an exemption from such
        registration is available; (c) Optionee understands that the Company is
        under no obligation to register the Option or the Option Shares; (d)
        Optionee understands that the Option and the Option Shares have not been
        qualified under the securities laws of any state and are to be offered
        and sold pursuant to an exception from qualification under applicable
        state securities laws; and (e) Optionee understands that the Company is
        relying


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        upon the truth and accuracy of the foregoing representations and
        warranties in granting the Option to Optionee.

4.      No Employment Rights. This Agreement gives Optionee no right to be
        retained as an employee of the Company and/or its Subsidiaries.

5.      Terms of the Option Plan. Optionee understands that the Option Plan
        includes important terms and conditions that apply to the Option. Those
        terms include: important conditions to the right of Optionee to exercise
        the Option; important restrictions on the ability of Optionee to
        transfer the Option or to Transfer any of the Shares of Option Stock
        received upon exercise of the Option; and early termination of the
        Option following the occurrence of certain events, including Optionee no
        longer being an employee, director, consultant or independent contractor
        to or of the Company or its Subsidiaries. OPTIONEE ACKNOWLEDGES HAVING
        READ THE OPTION PLAN, AGREES TO BE BOUND BY ITS TERMS, AND MAKES EACH OF
        THE REPRESENTATIONS REQUIRED TO BE MADE BY OPTIONEE UNDER IT. OPTIONEE
        FURTHER ACKNOWLEDGES THAT THE COMPANY HAS GIVEN NO TAX ADVICE CONCERNING
        THE OPTION AND HAS ADVISED OPTIONEE TO CONSULT WITH HIS OR HER OWN TAX
        OR FINANCIAL ADVISOR ABOUT THE TAX TREATMENT OF THE OPTION AND ITS
        EXERCISE.

6.      Miscellaneous. Capitalized terms not otherwise defined in this Agreement
        will have the meanings set forth in the Option Plan. Neither this
        Agreement nor the Option is assignable by either party, except as
        expressly provided herein. All of the covenants and provisions of this
        Agreement by or for the benefit of the Company or Optionee shall bind
        and inure to the benefit of their respective successors. This Agreement
        (including the Option Plan) constitutes the final and complete
        expression of all of the terms of the understanding and agreement
        between the parties hereto concerning the subject matter hereof. This
        Agreement may not be modified, amended, altered or supplemented except
        by means of the execution and delivery of a written instrument mutually
        executed by the Company and Optionee. This Agreement shall be construed
        and governed by the substantive laws of the State of Delaware.

The parties hereby have entered into this Agreement as of the Grant Date.


                                      RADIATA, INC.


                                      By:
                                         ---------------------------------------
                                      Title: Vice President, CFO

                                     "OPTIONEE"



                                      -----------------------------------------
                                      Address:

                                      US Social Security #:
                                      Australian Tax File #: 483 448 823

Attachments:   (1)    Consent of Spouse
               (2)    1999 Stock Option Plan
Exhibit A:     Form of Notice of Exercise of Stock Option


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