Fascinating! I've just pulled down the tvbgone code (which is a nice little python script), and yeah, it doesn't use LIRC. Very nice. Their set of codes is very simple, and consists of entries like this:

In these entries, the first value is the carrier frequency, the second value is a string of indexes, and the third value is an array of microsecond timing pairs. Constructing a shut-off command is then just a matter of building up an array of timings by going through the string, and for each index, selecting the appropriate timing pair.

There are protocols for which this mechanism would be inconvenient (not everybody uses simple pulse/space timings to encode individual bits of data), but you could probably hack it to work with most devices.

There's one big problem with maintaining this code, though: I have no clue which TVs are supported and which are not. I can probably pick out a few -- some protocols have odd timing values that are easy to recognize -- but for most of them, it'd take some effort to determine exactly what device they are for. Which makes it awfully hard to know what needs to be added!

I'm probably not going to get involved with that code (I'm having a hard enough time making enough time for my own projects ), but it looks easy enough for just about anybody to play with if you'd like to mess around with IR.