UIM is described as 'Uim is a multilingual input method library, whose goal is to be a flexible development platform and useful user environment for input methods of all languages'. There are three alternatives to UIM for Linux and BSD. The best alternative is iBus, which is both free and Open Source. Other great apps like UIM are fcitx (Free, Open Source) and scim (Free, Open Source).
Fcitx ['fa?t?ks] is a input method framework with extension support. Currently it supports linux and Unix system, like freebsd. It has three builtin Input Method Engine, Pinyin, QuWei and Table-based input methods.
The Smart Common Input Method (SCIM) platform project provides not only a user friendly, full featured input method user interface for POSIX-style operating systems (including Linux, FreeBSD and other Unix), but also a development platform to make input method development easier.