Microsoft's Mac BU and FrontLine Systems have announced that Solver for Excel 2008 is now available for download.
Frontline Systems developed the original Solver for Excel on both Macintosh and Windows. For many years, we've offered Solver upgrades for Windows users, that have gotten more and more powerful over time -- but we haven't been active on the Mac. We're now applying more development resources to the Macintosh, motivated by the Mac's resurgence in the market and the move to Intel processors. But the catalyst for this move has been Microsoft's Mac Excel team.
Solver is an Excel add-in that allows linear programming / analysis tool for Excel which was initially released for the Mac when Excel 2004 shipped but was dropped from Excel 2008 due to its dependency on Visual Basic for Applications (VBA) support.
Microsoft has previously announced that VBA support will be coming back to Mac Office in the next version.
http://www.officeformac.com/blog/Solver-For-Excel-2008-Is-Available