The second generation of Fabric OS (4.0) was developed on a
PowerPC platform, and uses
MontaVista Linux, a Linux derivative with
real-time performance enhancements. With the advent of MontaVista, switches and directors have the ability of hot
firmware activation (without downtime for
Fibre Channel fabric), and many useful diagnostic commands. According to free software licenses terms, Brocade provides access to sources of distributed free software, on which Fabric OS and other Brocade's software products are based. ==Additional licensed products==