Houstonian here.
Houston has a huge tech presence, but it is all about enterprise infrastructure and auxiliary enterprise services, or highly specialized tech disciplines (the sort of things that OEM hardware manufacturers, NASA, etc. want). Most of the devs are either old school or .NET drones, and there's very little of the sort of dev scene that you see in places like the Bay Area. There's one notable hackerspace (TX/RX Labs).
There's not a 'scene' per se, and even groups that focus on things like datacenter/enterprise infrastructure don't really get much traction. Part of this is because a.) Houston has a multitude of separate central business districts that are reasonably distant from each other, and that b.) the greater Houston area is incomprehensibly HUGE (compared to what most people, even Americans, are used to). On a normal day without rush hour traffic, it can take nearly 1.5 hours to drive from what most Houstonians consider the West end of the 'Houston area' (Katy, TX) to the East end (La Porte or Baytown, TX). It's a 60 mile trip. With tech folks spread out all over this massive area, most people, especially those outside the inner-loop (I-610) don't really want to bother with commuting to meetups or events. Especially because the public transport infrastructure here is piss poor.