This is a customizable keychain generator. The keychain is made out of a word. If the word has a letter with a nice hole, you can omit the ring for the keyring. This uses (and bundles) my Hershey font OpenSCAD library.
Note the licensing on the Hershey library in the source code, which isn't fully compatible with Creative Commons -- but the restrictions are very, very slight. And it's not clear that font coordinates are copyrightable (in the US at least; but I am not a lawyer).
August 16, 2019: optimizations in Hershey library; different ring cross-sections
August 10, 2019: uses latest Hershey font library: nicer font names, Latin-1 accented characters supported
August 23, 2017: added rounded top option
August 19, 2017: smart ring and letter spacing (turn off smart overlap for legacy letter spacing); works much better with combinations like "Ta"
August 15, 2017: fixed "NAME" bug (again!)
August 14, 2017: customizable ring vertical position