Yes, Mirage’s involvement in GSoC and Outreachy is managed by the Xen project, which we’re really thankful for!
I’m failing to find where past Outreachy internships are listed on Outreachy’s site (currently their “alums” link just goes to a list of the current round participants), so here’s a summary from memory (yikes) dating from my first involvement with the project:
Jyotsna Prakash built some ec2 bindings (more on her blog) in 2014.
Mindy Preston (that’s me!) made a bad fuzzer and wrote a lot, also in 2014.
Kia built us an NTP client and server in 2016. She also wrote about it, but I’m having trouble finding her blog - perhaps someone else remembers where it lives?
Gina Maini worked on syslogs for Mirage, also in 2016.
Through GSoC we also had David Udelson work on a REST API for Irmin this summer.
If I forgot anyone, please do correct and forgive me - it’s still pre-coffee time in my timezone!