Sumatra PDF

Sumatra PDF - PDR Reader

SumatraPDF is a compact PDF reader, it can show ePub, mobi, chm and other document formats as well. There is a 32bit and a 64 bit version for Windows.
It is free software licensed under GNU GPL v3.
The development is mainly in C++.
The homepage is sumatrapdfreader.org
SumatraPDF can be used as portable application. There is a version for PortableApps.
https://portableapps.com/apps/office/sumatra_pdf_portable
The development started in 2006 with version 0.1. The latest release is 3.1.2 from Aug 2016. In total 43 releases have been published. This is an enormous achievement in 11 years. But the last release

Sumatra Commits

Sumatra commits per month: 2007 - 2018

The commits begin with the first one in July 2007 by Krzysztof Kowalczyk (blue color). He founded this project. Development was steady ongoing. The activity increased a lot when a second developer joined 2 years later in July 2009, zeniko (green color). They worked together for nearly 7 years and 28 releases on SumatraPDF. Those two developers did more than 97% of all commits. There were 20 other authors involved in the development (purple color). The work from other developers are sometimes single commits in one month. This is difficult to see on the chart above.

Sumatra Team

The Team Chart is better suited to show the team structure. Each developer who has at least one commit in a month is shown regardless of the number of commits.
Blue are the main developers kjk and zeniko. Yellow is a developer how has added LaTeX support in 2008. Red are developers who have added smaller parts.
The development team never had more than 3 people.
2016 was the year with the lowest development activity, but in 2017 development has increased and goes on with 470 commits since the last release. A new release is past due.