jSpeech is a Java library designed to integrate Speech-to-Text (STT) capabilities, command control, and diarization (speaker identification) into applications in a simple, modular, and decoupled way.
JAVIER is a JAvascript Voicexml InterpretER, designed (but not restricted) to run inside a web browser, its main engine has less than 1000 lines of code. It's maybe, the tiniest but (almost) FULL VoiceXML implementation.
jATLAS is a Javaimplementation of ATLAS [Architecture and Tools for Linguistic Analysis Systems]. For more information, see http://jatlas.sourceforge.net.