AMENDED AND RESTATED EMPLOYMENT AGREEMENT

EXHIBIT 10.21

AMENDED AND RESTATED EMPLOYMENT AGREEMENT

This Amended and Restated Employment Agreement (the “Agreement”) is entered into as of April 8, 2009 (the “Effective Date”) by and between William Slater (“Executive”) and Saba Software, Inc., a Delaware corporation (the “Company”), and amends and restates in its entirety that Employment Agreement dated as of December 8, 2008 (the “Existing Agreement”).

R E C I T A L S

A. Executive and the Company entered into the Existing Agreement to set forth the terms of Executive’s employment with the Company as Chief Financial Officer.

B. The Company believes that maintaining sound management is essential to protect and enhance the best interests of the Company and its stockholders.

C. The Company desires assurance of the continued association and services of Executive in order to retain Executive’s experience, skills, abilities, background and knowledge, and is willing to engage Executive’s services on the terms and conditions set forth in this Agreement.

E. Executive desires to continue to be in the employ of the Company, and is willing to accept such employment on the terms and conditions set forth in this Agreement.

F. Executive and the Company desire to amend and restate the Existing Agreement upon the terms and conditions more fully set forth herein.

A G R E E M E N T

NOW, THEREFORE, based on the foregoing recitals and in consideration of the commitments set forth below, Executive and the Company agree as follows:

1.1. Term . The Company hereby employs Executive to render services to the Company in the position of Chief Financial Officer, reporting directly to the Chief Executive Officer of the Company, for the period commencing on the Effective Date and ending on the date Executive’s employment is terminated under this Agreement (the “Term”). The Company and Executive hereby acknowledge that either of them may terminate Executive’s term of Employment for any reason or no reason at all.

1.2. Position . The duties of this position shall include such duties and responsibilities as are reasonably assigned to Executive by the Chief Executive Officer, including but not limited to those customarily performed by chief financial officers of similarly situated corporations. Executive agrees to serve in a similar capacity for the benefit of any of the Company’s direct or indirect, wholly-owned or partially-owned subsidiaries or affiliates. Additionally, Executive shall serve in such other capacity or capacities as the Chief Executive Officer may from time to time prescribe. During his employment by the Company, Executive shall, subject to Section 1.3, devote his full energies, interest, abilities and productive time to the proper and efficient performance of his duties under this Agreement.

1.3. Other Activities . Except upon the prior written consent of the Chief Executive Officer of the Company, Executive will not (i) accept any other employment, or (ii) engage, directly or indirectly, in any other business activity (whether or not pursued for pecuniary advantage) that is or may be in conflict with, or that might place Executive in a conflicting position to that of, the Company. Notwithstanding the foregoing, Executive shall be permitted to engage in occasional professional or charitable activities outside the scope of his employment with the Company so long as such activities (A) do not conflict with the actual or proposed business of the Company or any of its subsidiaries or affiliates, and (B) do not affect the performance of his duties hereunder. In addition, subject to the prior written consent of the Chief Executive Officer and the Board of Directors of the Company and subject to Executive’s fiduciary duties to the Company, Executive shall be permitted to serve as a director of other corporations provided that their businesses are not competitive with the actual or proposed business of the Company or any of its subsidiaries or affiliates and provided further that Executive’s service as a director of such other corporations does not interfere with his performance of his duties hereunder. Any such prior written consent may be subsequently revoked in the event that the Board of Directors determines, in good faith, that Executive’s position as a director of any such other corporation has developed into a conflict of interest.

1.4. Proprietary Information . Executive recognizes that his employment with the Company will involve contact with information of substantial value to the Company, which is not generally known in the trade, and which gives the Company an advantage over its competitors who do not know or use it. Executive has previously executed and delivered to the Company a copy of the Company’s standard form of Employee Proprietary Information and Inventions Agreement (the “Employee Proprietary Information and Inventions Agreement”).

2.1. Base Salary . In consideration of the services to be rendered under this Agreement, while employed by the Company, Company shall pay Executive an initial base annual salary of two hundred seventy thousand dollars ($270,000.00), less standard deductions and withholdings, payable in regular periodic payments in accordance with Company payroll policy. Such salary shall be prorated for any partial month of employment on the basis of a 30-day fiscal month. Such base salary shall be subject to annual review by the Board of Directors in consultation with the Chief Executive Officer.

2.2. Bonus . Executive will be eligible to receive bonuses totaling fifty percent (50%) of his base salary annually (such annual amount, the “Target Bonus”), the exact amount of each such bonus to be determined by the Board of Directors in consultation with the Chief Executive Officer based upon Executive achieving certain performance criteria and the Company achieving specific financial goals, in each case to be determined by the Board of Directors in consultation with the Chief Executive Officer. Any such bonus shall be payable at the direction of the Board of Directors either after the end of the fiscal year or quarterly after the end of each fiscal quarter, and shall be prorated for partial fiscal periods. Such bonuses shall in

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no event be paid later than 2  ¹ / 2 months after the close of the Company’s fiscal year in which such bonus was earned. In addition, Executive shall be eligible for such additional bonuses as may be awarded by the Board of Directors in its sole discretion from time to time in consultation with the Chief Executive Officer.

2.3. Stock Option . Executive has been granted a stock option to purchase 300,000 shares of the Company’s Common Stock at the market price in effect on the date the Board of Directors approved the grant pursuant to the Company’s standard form of Stock Option Agreement (the “Stock Option Agreement”). Twenty-five percent (25%) of the shares subject to the stock option will vest on the one (1) year anniversary of the Effective Date and the remaining seventy-five percent of the shares subject to the stock option will vest in 12 equal quarterly installments with the first installment vesting one quarter after the first anniversary of the Effective Date of this employment agreement. Vested options subject to the Stock Option Agreement will remain exercisable for a period of six (6) months after Executive’s termination of employment other than for Cause, subject to the terms of the stock option.

2.4. Benefits . Executive shall be entitled to participate in the Company’s group medical, dental, life insurance, 401(k), deferred compensation or other benefit plans and programs on the same terms and conditions as other members of the Company’s senior executive management. Executive shall be provided such perquisites of employment, including at least four (4) weeks paid vacation, and all paid holidays and sick leave as are provided to all other members of the Company’s senior executive management. Executive shall be entitled to reimbursement of all reasonable expenses incurred by Executive in the performance of his duties hereunder, in accordance with the policies and procedures established by the Company from time to time, and as may be amended from time to time.

Company or Executive may terminate Executive’s employment with Company at any time for any reason, including no reason at all, notwithstanding anything to the contrary contained in or arising from any statements, policies, or practices of Company relating to the employment, discipline, or termination of its employees. This at-will employment relationship cannot be changed except in writing signed by a duly authorized officer of the Company other than Executive. This Section 3 shall survive any termination or expiration of this Agreement.

4.1. Termination by Executive . Executive may terminate his employment upon notice to the Company. In the event that Executive elects to terminate his employment other than for Good Reason (as defined below) in accordance with Section 4.3 or 4.4, the Company shall pay Executive all base salary due and owing and all other accrued but unpaid benefits (e.g., accrued vacation) through the last day actually worked and thereafter the Company’s obligations under this Agreement shall terminate.

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4.2. Termination by the Company for Cause . In the event that the Company terminates Executive’s employment for Cause, the Company shall pay Executive all base salary due and owing and all other accrued but unpaid benefits (e.g., accrued vacation) through the last day actually worked and thereafter the Company’s obligations under this Agreement shall terminate. For the purposes of this Agreement, termination shall be for “Cause” if (i) Executive refuses or fails to act in accordance with any lawful order or instruction of the Chief Executive Officer, and such refusal or failure to act has not been cured within 30 days of notice of such disobedience, (ii) Executive fails to devote reasonable attention and time during normal business hours to the business affairs of the Company or Executive is reasonably determined by the Board of Directors to have been unfit (other than as a result of an Incapacity), unavailable for service (other than as a result of an Incapacity) or grossly negligent in connection with the performance of his duties on behalf of the Company, which unfitness, unavailability or gross negligence has not been cured within 30 days of notice of the same; (iii) Executive is reasonably determined by the Board of Directors to have committed a material act of dishonesty or willful misconduct or to have acted in bad faith to the material detriment of the Company in connection with the performance of his duties on behalf of the Company; (iv) Executive is convicted of a felony or other crime involving dishonesty, breach of trust, moral turpitude or physical harm to any person, or (v) Executive materially breaches any agreement with the Company which breach has not been cured within 30 days notice of the same. For purposes of this Agreement, the term “without Cause” shall mean termination of Executive’s employment for reasons other than for “Cause.”

4.3. Termination by the Company without Cause or by Executive for Good Reason . In the event that the Company terminates Executive’s employment without Cause or Executive terminates his employment for Good Reason, and in either case a Separation (as defined below) occurs, the Company shall pay Executive all base salary due and owing and all other accrued but unpaid benefits (e.g., accrued vacation) through the last day actually worked, and Executive shall be entitled to receive the severance payments and benefits set forth below in this Section 4.3; provided, however, that such severance and benefits are conditioned on Executive’s execution and non-revocation of a release agreement, the form of which is attached hereto as Exhibit A , and thereafter the Company’s obligations under this Agreement shall terminate. Executive shall execute and return such release agreement no later than sixty (60) days from the date of Executive’s Separation (the “Release Date”). For purposes of this Agreement, the term “Separation” shall mean a “separation from service,” as defined in the regulations under Section 409A of the Internal Revenue Code of 1986, as amended (the “Code”).

4.3.1. Target Bonus and Base Salary . On the date of the termination of Executive’s employment, the Company shall pay to Executive, in a single lump-sum payment, subject to standard deductions and withholdings, Executive’s Target Bonus for any partially completed bonus period, as if the applicable performance criteria and Company financial goals had been achieved completely, pro rated based on the number of days actually elapsed through the date of termination in the bonus period in which such termination occurs. In addition, the Company shall pay to Executive an amount equal to that number of months of Executive’s then current base salary equal to the sum of six (6) months plus one month for every twelve month period Executive has been employed by the Company prior to the date of termination (which sum shall not exceed twelve (12) months) (collectively, the “Severance Months”), less all applicable standard deductions and withholdings. Such amount payable in

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accordance with the preceding sentence shall be payable in the form of salary continuation. Subject to timely receipt by the Company of the executed release agreement, the first payment of any such salary continuation shall be made within ten (10) days after the Release Date and shall include any salary continuation payments that accrued to Executive post-termination of employment but that were not paid pending receipt of the executed release agreement.

4.3.2. Group Medical Coverage . The Company shall, following the Executive’s timely election, provide the Executive with continued coverage, for that number of months after termination of Executive’s employment equal to the number of Severance Months, under the Company’s group health insurance plans in effect upon termination of Executive’s employment in accordance with the provisions of the Consolidated Omnibus Budget Reconciliation Act of 1985 (“COBRA”), at no cost to Executive. If COBRA or similar benefits are not available by law during any portion of the remainder of such six-month period, then the Company shall pay Executive each month during which COBRA or similar benefits are not available by law an amount equal to the premium paid by Executive for the last month during which such COBRA or similar benefits were available.

4.3.3. Acceleration of Vesting of Stock Option . On the date of Executive’s termination of employment, the vesting of the shares subject to any stock option then held by Executive, including without limitation the option described in Section 2.4, shall accelerate as though Executive had remained in employment for an additional twelve (12) months.

4.4. Termination by the Company without Cause or by Executive for Good Reason at the Time of or within 12 Months After a Change of Control . In the event that, at the time of or within twelve (12) months after a Change of Control (as defined below), the Company terminates Executive’s employment without Cause or Executive terminates his employment for Good Reason, and in either case a Separation occurs, the Company shall pay Executive all base salary due and owing and all other accrued but unpaid benefits (e.g., accrued vacation) through the last day actually worked, and Executive shall be entitled to receive the severance payments and benefits set forth below in this Section 4.4; provided, however, that such severance and benefits are conditioned on Executive’s execution and non-revocation of a release agreement, the form of which is attached hereto as Exhibit A , and thereafter the Company’s obligations under this Agreement shall terminate. Executive shall execute and return such release agreement no later than the Release Date. Executive agrees that he may be required to travel from time to time as required by the Company’s business and that such travel shall not constitute grounds for Executive to terminate his employment for Good Reason. For the purposes of this Agreement:

“Good Reason” means any of the following by the Company or any successor with respect to Executive: (1) a material reduction in salary or target compensation without Executive’s consent; (2) the relocation of work location to a location more than fifty miles from the Company’s current work location without Executive’s consent; or (3) there is a material diminution of Executive’s responsibilities with the Company, or a material change in Executive’s reporting responsibilities or title, in each case without Executive’s consent. A condition shall not be considered “Good Reason” unless Executive gives the Company written notice of such condition within ninety (90) days after such condition comes into existence and the Company fails to remedy such condition within thirty (30) days after receiving Executive’s written notice.

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“Change of Control” means the occurrence of any of the following events:

(i) The sale, exchange, lease or other disposition or transfer of all or substantially all of the consolidated assets of the Company to a person or group (as such terms are defined or described in Sections 3(a)(9) and 13(d)(3) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) which will continue the business of the Company in the future; or

(ii) A merger or consolidation involving the Company in which the shareholders of the Company immediately prior to such merger or consolidation are not the beneficial owners (within the meaning of Rules 13d-3 and 13d-5 promulgated under the Exchange Act) of more than 50% of the total voting power of the outstanding voting securities of the corporation resulting from such transaction in substantially the same proportion as their ownership of the total voting power of the outstanding voting securities of the Company immediately prior to such merger or consolidation; or

(iii) The acquisition of beneficial ownership (within the meaning of Rules 13d-3 and 13d-5 promulgated under the Exchange Act) of at least 50% of the total voting power of the outstanding voting securities of the Company by a person or group (as such terms are defined or described in Sections 3(a)(9) and 13(d)(3) of the Exchange Act).

For purposes of this Section 4.4, the term Company shall include any successor to Saba Software, Inc., a Delaware corporation.

4.4.1. Target Bonus and Base Salary . On the date of the termination of Executive’s employment, the Company shall pay to Executive, or to Executive’s beneficiaries or estate as appropriate, in a single lump-sum payment, subject to standard deductions and withholdings, Executive’s Target Bonus for any partially completed bonus period, as if the applicable performance criteria and Company financial goals had been achieved completely, pro rated based on the number of days actually elapsed through the date of termination in the bonus period in which such termination occurs. In addition, the Company shall pay to Executive, or to Executive’s beneficiaries or estate, as appropriate, the sum of (i) twelve (12) months of Executive’s then current base salary , and (ii) the Target Bonus amount, less all applicable standard deductions and withholdings. Such amounts payable in the preceding sentence shall be payable in the form of salary continuation (with amounts attributable to the Target Bonus prorated monthly). Subject to timely receipt by the Company of the executed release agreement, the first payment of any such salary continuation shall be made within ten (10) days after the Release Date and shall include any salary continuation payments (including amounts attributable to the Target Bonus) that accrued to Executive post-termination of employment but that were not paid pending receipt of the executed release agreement.

4.4.2. Acceleration of Vesting of Stock Option . On the date of termination of Executive’s employment, 100% of the shares subject to any stock option then held by Executive, including without limitation, the option described in Section&nb