For Linux there is the Cell SDK, but that isn't too helpful for the GameOS part of the PS3 unfortunately. Cell Programming Tutorial - IBM
IBM has a site that was put up shortly after the PS3 went to market, aimed at OtherOS programmers.
Summary: Meet the Cell Broadband Engine™ (Cell BE) processor from a compiler-writer's perspective, and get a bird's-eye view of a number of the unique challenges it poses in this first tutorial of a five-part series.
Summary: This tutorial discusses specific issues in optimizing code to run effectively on the Synergistic Processor Elements (SPEs) in the Cell Broadband Engine™ (Cell BE) processor.
Summary: This tutorial discusses the compiler issues in optimizing code to run efficiently on SIMD-capable processors. In particular, it shows how to optimize code that must run both on the VMX SIMD engine of the PowerPC® core of the Cell Broadband Engine (Cell BE) processor, and also on the SIMD-only Synergistic Processor Elements (SPEs).
Summary: This part discusses ways to partition code to run across the multiple cores available in a Cell Broadband Engine™ (Cell BE) processor. It gives particular attention to efficient partitioning of code to allow larger programs or data sets to be manipulated using the 256KB of local store available on the Synergistic Processor Elements (SPEs).
Summary: This last tutorial discusses techniques for managing data in the local store of the Synergistic Processor Elements (SPEs) of a Cell Broadband Engine (Cell BE) processor. Learn particular techniques such as double-buffering and maintaining a reasonably efficient software cache.
You can download all this tutorials as a pdf on one of these mirrors (1MB): http://rapidshare.com/files/416223029/cell.zip http://ul.to/39b2fq http://www.megaupload.com/?d=0BWIWG1N