IFDB, the Interactive Fiction Database, is a web site created by Mike Roberts in October 2007 for person-to-person recommendations about IF games. IFDB users can edit the database of games, create Recommended Lists, associate "tags" (keywords) with the games, add reviews and ratings, etc. There's also a tool called the Download Adviser, which makes it easier to download and install games. See the R*IF thread.
In September 2009, a major upgrade added several new features to IFDB. Users can now add competition pages, award pages, club pages, and news items. There's also more places to add comments, see who's playing what (subject to privacy settings), several RSS feed options, displays of tag counts, and a new option to mark games you're not interested in.
In February 2021, Dan Fabulich announced that the Interactive Fiction Technology Foundation was adopting IFDB from Mike Roberts. IFDB was moved from ifdb.tads.org to its new home at ifdb.org on February 23, 2021.
A TUID is a tads.org unique identifier, used by IFDB to uniquely identify a game in its database. It may be up to 16 characters long, a random mix of letters and digits assigned by the IFDB software when the game's page is created. The TUID for a game is listed in the Details section of a game page on IFDB. See What's a TUID? for more info.
An IFID is an identifier that is coded into a game by the author, to the requirements described by the Treaty of Babel, to provide a unique, permanent, and universal way to refer to the game in all of its versions. The chief difference is function; the TUID refers to the game page in the IFDB database, whereas the IFID refers to the game itself.
- IFDB: The IFID is listed in the Details section of a game page (right above the TUID).
- IFWiki: The IFIDs listed in Category: Works by IFID create redirects of the form IFID:IFID to point to their appropriate work pages.