So, it's nearing the end of 2013, what are your opinions of .IO domains?

As a programmer, I've seen .io a lot in the industry lately. In the context of computing, I/O commonly means input/output, so it's a techie-appealing TLD. Has anyone tested the waters here? I assume the investor-to-investor potential is minimal, but investor-to-end-user could work.

Here are some established sites that I've seen recently:

cex.io - virtual currency mining
docker.io - server virtualization
github.io - user sites are hosted at ____.github.io; popular for open source

docker.io and cex.io could've made for good investments; github.io is obviously just a brand name.

Here's some more info about the increasing popularity of .io: The Rise of .io Domain Names for APIs

Most of the obvious programmer-ish named have been scooped up, but there's plenty of room if you're even mildly creative. Of course, programmers are going to love messing with the new gTLDs, so I wouldn't make any long-term investments. Flip fast.