Promissory Note - Akamai Technologies Inc. and Timothy Weller

                                 PROMISSORY NOTE
                                 ---------------

                                                                   July 23, 1999
$2,619,750                                                    New York, New York

     FOR VALUE RECEIVED, Timothy Weller (the 'Maker'), promises to pay to Akamai
Technologies, Inc. (the 'Company'), or order, at its offices or at such other
place as the holder of this Note may designate, the principal sum of $
2,619,750, together with interest on the unpaid principal balance of this Note
from time to time outstanding at the rate of 6.1% per year, compounded annually,
until paid in full. Principal and interest shall be paid in full on July 23,
2009; provided, however, if the Maker sells any shares of the Company, he shall
make a prepayment on this Note equal to the proceeds of such sale (net of
taxes), such payment applied first to accrued and unpaid interest and then to
principal until paid in full.

     Interest on this Note shall be computed on the basis of a year of 365 days
for the actual number of days elapsed. All payments by the Maker under this Note
shall be in immediately available funds.

     This Note shall become immediately due and payable without notice (except
as provided in paragraph (1) below) or demand upon the occurrence at any time of
any of the following events of default (individually, 'an Event of Default' and
collectively, 'Events of Default'):

     (1)  default in the payment or performance of this or any other liability
          or obligation of the Maker under a written contract to the holder that
          is not cured within 30 days after written notice of default thereof,
          including the payment when due of any principal, premium or interest
          under this Note;

     (2)  the insolvency of the Maker, or the appointment of a receiver or
          custodian for the Maker or any part of its property if such
          appointment is not terminated or dismissed within thirty (30) days;

     (3)  the institution against the Maker or any indorser or guarantor of this
          Note of any proceedings under the United States Bankruptcy Code or any
          other federal or state bankruptcy, reorganization, receivership,
          insolvency or other similar law affecting the rights of creditors
          generally, which proceeding is not dismissed within thirty (30) days
          of filing; or

     (4)  the institution by the Maker or any indorser or guarantor of this Note
          of any proceedings under the United States Bankruptcy Code or any
          other federal or state bankruptcy, reorganization, receivership,
          insolvency or other similar law affecting the rights of creditors
          generally or the making by the Maker or any indorser or guarantor of
          this Note of a composition or an assignment or trust mortgage for the
          benefit of creditors.





     Upon the occurrence of an Event of Default, the holder shall have then, or
at any time thereafter, all of the rights and remedies afforded by the Uniform
Commercial Code as from time to time in effect in the Commonwealth of
Massachusetts or afforded by other applicable law.

     All payments by the Maker under this Note shall be made without set-off or
counterclaim and be free and clear and without any deduction or withholding for
any taxes or fees of any nature whatever, unless the obligation to make such
deduction or withholding is imposed by law. The Maker shall pay and save the
holder harmless from all liabilities with respect to or resulting from any delay
or omission to make any such deduction or withholding required by law.

     No reference in this Note to any guaranty or other document shall impair
the obligation of the Maker, which is absolute and unconditional, to pay all
amounts under this Note strictly in accordance with the terms of this Note.

     The Maker agrees to pay on demand all costs of collection, including
reasonable attorneys' fees, incurred by the holder in enforcing the obligations
of the Maker under this Note.

     No delay or omission on the part of the holder in exercising any right
under this Note shall operate as a waiver of such right or of any other right of
such holder, nor shall any delay, omission or waiver on any one occasion be
deemed a bar to or waiver of the same or any other right on any future occasion.
The Maker and every indorser or guarantor of this Note regardless of the time,
order or place of signing waives presentment, demand, protest and notices of
every kind and assents to any extension or postponement of the time of payment
or any other indulgence, to any substitution, exchange or release of collateral,
and to the addition or release of any other party or person primarily or
secondarily liable.

     This Note may be prepaid in whole or in part at any time or from time to
time. Any such prepayment shall be without premium or penalty.

     None of the terms or provisions of this Note may be excluded, modified or
amended except by a written instrument duly executed on behalf of the holder
expressly referring to this Note and setting forth the provision so excluded,
modified or amended.

     All rights and obligations hereunder shall be governed by the laws of the
Commonwealth of Massachusetts and this Note is executed as an instrument under
seal.



                                              /s/ Timothy Weller
                                              -------------------------------
                                              Timothy Weller


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