TRF is a language transformation file format used LFToolkit software. TRF is one of the two formats (the other being XML) used by said application. TRF file structure is divided into three section: variables, inputs, and transformation rules. Application’s algorithm analyzes input data and transforms it into English sentences based on supplied transformation rules.

LFToolkit is written in Java for Windows XP. It requires Java Xerces2 parser to be installed on the system. LFToolkit can be used form the command line. Example TRF files are available on developer’s website.