NOTE GUARANTEE

Exhibit 10.5

NOTE GUARANTEE

For value received, the undersigned hereby, jointly and severally with all other Guarantors of the Notes, unconditionally guarantees to each Holder of a Note authenticated and delivered by the Trustee and to the Trustee and its successors and assigns, irrespective of the validity and enforceability of the Indenture, the Notes or the obligations of the Issuer hereunder or thereunder, that: (a) the principal of, interest, premium and Liquidated Damages, if any, on the Notes shall be promptly paid in full when due, whether at maturity, by acceleration, redemption or otherwise, and interest on the overdue principal of and interest on the Notes, if any, if lawful, and all other obligations of the Issuer to the Holders or the Trustee hereunder or thereunder shall be promptly paid in full or performed, all in accordance with the terms hereof and thereof; and (b) in case of any extension of time of payment or renewal of any Notes or any of such other obligations, that same shall be promptly paid in full when due or performed in accordance with the terms of the extension or renewal, whether at stated maturity, by acceleration or otherwise. Failing payment when due of any amount so guaranteed or any performance so guaranteed for whatever reason, the undersigned shall be jointly and severally obligated with all other Guarantors to pay the same immediately. The undersigned agrees that that this is a guarantee of payment and not a guarantee of collection.

This Note Guarantee will become effective in accordance with the Indenture and its terms shall be evidenced therein. The validity and enforceability of this Note Guarantee shall not be affected by the fact that it is not affixed to any particular Note. Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Indenture dated as of November 23, 2005, among Sunshine Acquisition II, Inc., a Delaware corporation, SS&C Technologies, Inc., a Delaware corporation, the Guarantors party thereto and Wells Fargo Bank, National Association, as trustee, as supplemented by the First Supplemental Indenture dated as of April 27, 2006, the Second Supplemental Indenture dated as of September 1, 2009, the Third Supplemental Indenture dated as of December 22, 2009, the Fourth Supplemental Indenture dated as of April 12, 2010 and the Fifth Supplemental Indenture dated as of April 14, 2011 (as further amended or supplemented, the “Indenture”).

THIS NOTE GUARANTEE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAW OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY. The undersigned hereby agrees to submit to the jurisdiction of the courts of the State of New York in any action or proceeding arising out of or relating to this Note Guarantee.

This Note Guarantee is subordinated in right of payment, in the manner and to the extent set forth in the Indenture, to the prior payment in full in cash or Cash Equivalents of all Guarantor Senior Debt, whether outstanding on the date of the Indenture or thereafter created, incurred, assumed or guarantee.

This Note Guarantee is subject to release upon the terms set forth in the Indenture.

[Note Guarantee]