Before talking about the changes in the program itself, I want to introduce the two people who have done the majority of the work in this release. These folks have generously volunteered their time and considerable expertise to make the program better. I'd like to acknowledge them here so that they can get the credit they have earned.
First, Helmut Grohne has been working on the code since 2013, including doing a major update of the fuzzy hashing engine. In his words, hacks on free software related to Debian and on software related to quality assurance in general. His current pet project is making the core of Debian cross buildable, see https://wiki.debian.org/HelmutGrohne/rebootstrap
Second, Tsukasa OI has written several improvements and major bug fixes in the fuzzy hashing engine. You will find several of his innovations in the latest release, described below. These made ssdeep faster, behave properly on unusual files, and in general, a better program.
Both of these people have made significant improvements in the program for version 2.13. In this release we've added some new features and fixed a few bugs. The most visible change is that the bug fixes will change the hash computation and hash comparisons for a small number of files. First, the program can now handle inputs up to 192 GB. Previously both were limited to much smaller sizes. Next, the hash generation and comparison functions have been improved when working with relatively simple files. These can be small files or files with low entropy. Finally, we've fixed some portability issues for getting the program to compile and run on different systems. Please let us know if you have any questions about what we've done or have ideas on future enhancements.
Finally, I am moving the project to Github. There are several reasons for this change, but I am hoping that the new UI will enable us to develop the program more quickly and more openly share it with the community. The move will take some time, and a little while longer to restore the releases. I'll do my best to get things up and running again quickly, but ask for your patience during this process!