LDC develops tools to support evolving annotation tasks. All tools distributed by LDC are available at no cost under an open source license.

• AGTK, Annotation Graph Toolkit [1]: Annotation Graphs are a formal framework for representing linguistic annotations of time series data. They abstract away from file formats, coding schemes and user interfaces, providing a logical layer for annotation systems. AGTK is a toolkit for using the Annotation Graph model. AGTK is made available under the Common Public License [2].
• CTK, Champollion Toolkit [3]: CTK aims to provide ready-to-use parallel text sentence alignment tools for as many language pairs as possible. CTK is made available under the GNU General Public License, version 3.0 [4].
• LDC Word Aligner [5]: A tool used to build manual word alignments. LDC Word Aligner is made available under the GNU General Public License, version 3.0 [4].
• SPHERE Conversion Tools [6]: Programs for converting NIST SPHERE speech files to other formats.
• XTrans [7]: A tool that supports manual transcription across multiple channels, languages and platforms. XTrans is made available under the GNU General Public License, version 3.0 [4].