difference from PAQ6 is it uses a neural network to combine models rather than a gradient descent mixer. Another feature is PAQ7's ability to compress embedded jpeg and bitmap images in Excel-, Word- and pdf-files. PAQ8A was released on January 27, 2006, PAQ8C on February 13, 2006. These were experimental pre-release of anticipated PAQ8. It fixed several issues in PAQ7 (poor compression in some cases). PAQ8A also included model for compressing (x86) executables. PAQ8F was released on February 28, 2006. PAQ8F had 3 improvements over PAQ8A: a more memory efficient context model, a new indirect context model to improve compression, and a new user interface to support drag and drop in Windows. It does not use an English dictionary like the PAQ8B/C/D/E variants. PAQ8G was released March 3, 2006 by Przemyslaw Skibinski. PAQ8G is PAQ8F with dictionaries added and some other improvements as a redesigned TextFilter (which does not decrease compression performance on non-textual files) PAQ8H was released on March 22, 2006 by Alexander Ratushnyak and updated on March 24, 2006. PAQ8H is based on PAQ8G with some improvements to the model. PAQ8I was released on August 18, 2006 by Pavel L. Holoborodko, with bug fixes on August 24, September 4, and September 13. It added a grayscale image model for PGM files. PAQ8J was released on November 13, 2006 by Bill Pettis. It was based on PAQ8F with some text model improvements taken from PAQ8HP5. Thus, it did not include the text dictionaries from PAQ8G or PGM model from PAQ8I. Serge Osnach released a series of modeling improvements: PAQ8JA on November 16, 2006, PAQ8JB on November 21, and PAQ8JC on November 28. PAQ8JD was released on December 30, 2006 by Bill Pettis. This version has since been ported to 32 bit Windows for several processors, and 32 and 64 bit Linux. PAQ8K was released on February 13, 2007 by Bill Pettis. It includes additional models for binary files. PAQ8L was released on March 8, 2007 by Matt Mahoney. It is based on PAQ8JD and adds a DMC model. PAQ8O was released on August 24, 2007 by Andreas Morphis. Contains improved BMP and JPEG models over PAQ8L. Can be optionally compiled with SSE2 support and for 64-bit Linux. The algorithm has notable performance benefits under 64-bit OS. PAQ8P was released on August 25, 2008 by Andreas Morphis. Contains improved BMP model and adds a WAV model. PAQ8PX was released on