The Linker post for this episode is RTOSs and Brownies.
Joel Sherrill (@JoelSherrill) spoke with us about real time operating systems, free and open source software, interns, and space.
RTEMS home page and wiki
Google Summer of Code (the FAQ is the best part!) and ESA Summer of code (awesome tagline: In space no one can hear you code).
The LEON is the ESA Sparc core with open source VHDL and extensive use by ESA.
Some projects RTEMS is used on include the Magnetosphere Multiscale Mission, the ExPRESS Logistics Carrier, Mars Curiosity, and the Dawn spacecraft that is visiting the Ceres asteroid.