Resolver One

Resolver One is a Spreadsheet program created by Resolver Systems with the IronPython programming language. It is a desktop application, with a web server version, and intended as a platform for the rapid development of business applications.

It runs on Microsoft Windows, and is free for non-commercial use and for works released under a open-source license. Although it is not Open Source software and the source code is not released, the company has released one of its tools, Ironclad, under the MIT licence.

Resolver One is a "mash-up" of a spreadsheet and an IDE, combining a spreadsheet program with the Python programming language. Spreadsheets are turned into Python code and executed in real-time. Code can be mixed, using both Python and .NET libraries. Spreadsheets can also be exported as stand alone programs.

Resolver One is developed using extreme programming and other development techniques such as pair programming. As of March 2008, their codebase stood at 30 000 lines of code in production and 110 000 lines of code in the test framework.