FOSS is great. It allows any interested party to join and modify software to serve their needs, including local language supports.
In many cultures, including Thai, people are happy reading English messages in applications, but require applications to allow creating and editing "contents" in their own languages. For these cultures, language supports in infrastructure for text input, text rendering and printing, and some internal operations like sorting and text analysis, are essential, while message translation is optional.
So, when asked if Thai is supported by GNOME, I'd answer yes, because, through many development efforts in the past, you can now:
- Type Thai text in GNOME applications, with input sequence checking, and even correction (with Thai XIM and GTK+ im-xim bridge).
- See Thai text with quality rendering, with even OpenType font support (thanks to the Pango project).
- Read Thai text with proper line wrapping, or even word selection, despite the fact that Thai words are not delimited by spaces nor any punctuation marks (thanks to the LibThai project, with the wise API provision by Pango itself).
- Sort Thai words in applications according to the standard dictionary, as well as other cultural conventions such as date/time format (thanks to the Thai Locale project).
Unfortunately, Thai message translation in GNOME 2.10 is still far from complete. So, it's not listed as a "supported" language. But the fact is that many Thai people just don't care about message translation.
Nothing to complain here. Just a notice that my definition of "language support" might be different from the official one. :-)