Silkypix has announced a release candidate beta of their latest Windows-based Developer Studio Pro software. New in this version is support for Sigma's X3F file format, thus providing an alternative for SD and DP users for RAW development. Click below for the download link. This is beta software and as such the developers will welcome feedback particularly with regard to how it handles your SD14, DP1 and DP2 files. 

http://www.isl.co.jp/SILKYPIX/english/special/sigma/download/

This link will be active until the end of November 2009 during the testing phase of the software. As "Release Candidate" the software should be stable, but it is essentially a beta version. At present there is no Mac version listed of the Sigma compatible beta.