I recently read a book http://www.amazon.com/Scientific-Engineering-Cookbook-Cookbooks-OReilly/dp/0596008791/ref=sr_1_1?ie=UTF8&s=books&qid=1296593374&sr=8-1 - the Excel Scientific and Engineering Cookbook.
The 2 main tools that this book leveraged were the Data Analysis Pack and Excel Solver. I had previously been aquanted with Microsoft Solver Foundation - this is a full fledged API for solving optimization problems, and went beyond being a mere Excel plugin - it exposed a C# programmatic interface for in process and a web service interface for out of process integration.
were they the same? apparently not!
2 different solver frameworks for Excel:
http://www.solver.com/index.html
http://www.solverfoundation.com/
I contacted both vendors to get their perspectives.
Heres what the Excel Solver guys had to say:
"The Solver Foundation requires you to learn and use a very specific modeling language (OML).
The Excel solver allows you to formulate your optimization problems without learning any new language simply by entering the formulas into cells on the Excel spreadsheet, something that nearly everyone is already familiar with doing.
The Excel Solver also allows you to seamlessly upgrade to products that combine Monte Carlo Simulation capabilities (our Risk Solver Premium and Risk Solver Platform products) which allow you to include uncertainty into your models when appropriate.
Our advanced Excel Solver Products also have a number of built in reporting tools for advanced analysis of the your model and it's results"
And Heres what the Microsoft Solver Foundation guys had to say:
"
With the release of Solver Foundation 3.0, Solver Foundation has the same kinds of solvers (plus a few more) than what is found in Excel Solver. I think there are two main differences:
1. Problems are described differently. In Excel Solver the goals and constraints are specified inside the spreadsheet, in formulas. In Solver Foundation they are described either in .Net code that uses the Solver Foundation Services API, or using the OML modeling language in Excel.
2. Solver Foundation’s primary strength is on solving large linear, mixed integer, and constraint models. That is, models that contain arbitrary nonlinear functions (such as trig functions, IF(), powers, etc) are handled a bit better by the Excel Solver at this point.
"