Local tech communities (apart from GDG)

Hello!

I've tried to search for some tech communities in Waterloo that organizes regular meetups and stuff to talk about new interesting features about this industry.

I've been to the GDG DevFest today, but it seems too much revolving around Google stuffs and development.

Any Open Source enthusiasts in here, who know any communities and can drop some of the links of those groups? Things about Linux, System Admin, networking stuffs?

Regards,
Shravan