I had a couple classes like that, usually it was more at the semester boundary. E.g. my intro to compilers classes involved writing a compiler for a c-subset. The advanced compilers class built on that compiler by adding optimizations and such. My intro to systems class had a project that was to write a shell. My operating systems class had a project to add job management and pipes to the shell from the systems class. I really liked those projects you felt like you had something pretty substantial when you were done.