Part of the Animal Improvement Program, The MTDFREML programs are distributed in a text form sent as a set of attachments. Two different versions are currently supported, with the primary difference being the timing routines. The "PC" version uses the timing routines from the Microsoft Powerstation Fortran compiler. These routines are supported in the Digital/Compaq "upgrade" to that compiler, the Visual Fortran compiler. The other version has timing routines disabled. Please specify which version you would like when requesting the software. The sparse routines are a modified and reduced version of the Sparspak routines developed and modified by Alan George at University of Waterloo This modification included dealing with singular matrices, adapting the developments that Steve Kachman implemented in the original version. These new routines for use only with the MTDFREML programs. Please make sure to let us know if you are using the program. This can be done in several ways. Fill out the user information form on the world wide web home page or to FTP, complete, and mail or e-mail the userinfo.txt file. In order to keep track of researchers using MTDFREML programs are e-mailed on request. This allows us to contact users in the case of bugs or upgrades. Please send an e-mail to Dale Van Vleck requesting a copy of the software.