Both projects seem to be quite mature, but according to the git history, mineserver is older. The first commit of mineserver was on Oct. 12, 2010.

https://github.com/fador/mineserver/commit/399bca07f66b2882b...

The first MCServer commit was about a year later, on Oct. 3, 2011.

https://github.com/mc-server/MCServer/commit/cc2b15a2335db9a...