Built an operating system (named PintOS) in a group with three fellow classmates for our Operating Systems course. We built the Operating System to support threads (for example multi-threaded programs), user programs, virtual memory (using paging) and a file system (using Indexed Allocation similar to Unix.)
More information can be found here: http://www.cs.utexas.edu/users/ans/classes/cs439/projects/pintos/WWW/pintos.html#SEC_Contents