Similarly:
OS: openbsd (was slackware)
WM: cwm
Mail, file mgt, authoring: emacs
Agenda calendaring: orgmode
Writing: latex
Statistics: R
;-)
I switched from OpenBSD awhile ago to Linux because 1) OpenBSD is dog slow and 2) a lot of software doesn’t work right with it. However, it’s probably the nicest operating system I’ve ever used.