Lots of announcements coming out of Day 3 of the Professional Developers Conference in Los Angeles on Thursday. Microsoft officials have announced the first public beta of Windows Server 2003 Compute Cluster Edition is available for testers to download. Compute Cluster Edition is Microsoft's first supercomputing SKU of Windows. eWEEK has unearthed an interesting nugget buried in the product: The Message Passing Interface, which is a piece of bona fide open-source technology developed by a consortia of supercomputing vendors.