SRILM - The SRI Language Modeling Toolkit
SRILM is a toolkit for building and applying statistical language
models (LMs), primarily for use in speech recognition, statistical
tagging and segmentation, and machine translation.
It has been under development in the
SRI Speech Technology and Research Laboratory since 1995.
The toolkit has also greatly benefitted from its use and enhancements
Johns Hopkins University/CLSP summer workshops in
1995, 1996, 1997, and 2002 (see history).
These pages and the software itself assume that you know what statistical language modeling is. To learn about language modeling we recommend the textbooks
Either book gives an excellent introduction to N-gram
language modeling, which is the main type of LM supported by SRILM.
SRILM consists of the following components:
- A set of C++ class libraries implementing language models,
supporting data stuctures and miscellaneous utility functions.
- A set of executable programs built on top of these libraries to
perform standard tasks such as training LMs and testing them on data,
tagging or segmenting text, etc.
- A collection of miscellaneous scripts facilitating minor related tasks.
SRILM runs on UNIX and Windows platforms.
SRILM has been used in a great variety of statistical modeling
Others have published extensions to SRILM that add
SRILM is still under development. The documentation in particular
is work in progress. Best documented are the executable programs,
scripts, and file formats, in the form of UNIX-style manual pages. The libraries are
documented mostly in the source code. An overview of what the software
can do and its design philosophy can be found in the paper "SRILM - An
Extensible Language Modeling Toolkit", in Proc. Intl. Conf. Spoken
Language Processing, Denver, Colorado, September 2002
Links to other papers and tutorials, as well as frequently asked questions,
are also given
A recent paper summarizes updates
to SRILM since the 2002 paper.
We are releasing SRILM mainly because we have received requests for the
software from several researchers around the world. Therefore, there is
no guarantee of support. SRILM can be
downloaded free of charge
under an "open source community
license", meaning that you can use it freely for non-profit
purposes, as long as you share any changes you make with the rest of
the user community. For other uses please inquire about
Exchange of information among SRILM users, as well as some level of
technical support, is provided through the mailing list
Check the mailing list archive for
To subscribe and obtain more