Here are some other good website links, sorted by their primary language.

English
-Ticalc.org
The largest TI program archives on the web, since 1996.
-Cemetech
Another active TI-83 Plus ASM/BASIC and Casio PRIZM discussion forum, along with general hardware and computer talk.
-United-TI
General TI calculator help and programming forum, although not as active anymore.
-TI-BASIC Developer
The largest TI-BASIC documentation online, along with tutorials and an help-oriented forum.
-WikiTI
Great resource for TI-83/84+ ASM programmers.
-Axe Parser Wiki
Great resource for Axe Parser programmers.
-Hackspire
Great resource for TI-Nspire programmers and hackers.
-PrizmWiki
Great resource for Casio PRIZM fx-cg10/20 programmers and hackers.
-MaxCoderz
The source of major releases such as FFTOM, Desolate and the original Grayscale Package, although no longer active.
-Revolution Software
A smaller and less active TI-83 Plus forum, but still has major projects such as Wabbitcode and WabbitEmu in development.
-TI-Freakware
Home of Ultima V for the 68K and Pokémon Purple project. Although the site is not very active anymore, Pokémon Purple is still being worked on.
-Detached Solutions
A no longer active TI-83 Plus ASM development team and discussion. Home of MirageOS, Omnicalc and PuzzPack.
-Universal Casio Forum
Formerly a Casio programming board, now mainly oriented towards general calculator usage help.
-Texas Instruments
The official Texas Instruments calculator website.
-Casio Education
The official Casio calculator website.

French
-TI-Planet
The biggest source of TI news on the web. Has an active help and discovery discussion board for both TI and Casio.
-yAronet 68K forums
A large, formerly active TI-89, 92, 92+ and Voyage 200 development and help forum.
-Planète Casio
The most active Casio discussion on the web, mostly oriented towards the FX-9860G and Algebra FX series.
-Ti Softwares
A z80 and 68k programming team, with a library of games and math tools. Home to an online TI-82, 83 and 85 emulator.