25-29 August 2014, University of Aachen, Germany

By Olexandr Konovalov, SSI Fellow and Research Fellow at the Centre for Interdisciplinary Research in Computational Algebra (CIRCA), University of St Andrews

Background:

GAP is a software system for computational discrete algebra with particular emphasis on Computational Group Theory.

Highlights:

• Discussions on opening up the GAP development, on making new releases and transition to the next version of GAP which supports multithreading
• Coding sessions to work on particular functionality to appear in GAP and/or its packages. Good progress was achieved in all directions

Event report:

This was the first GAP Days event. It was open to the whole of the GAP community, including those who use GAP but never contributed to its development before, and to developers of software systems interfacing to/from GAP.

GAP developers have had no such open meetings of since the GAP Package Authors workshop in 2007 (except some smaller events on specific topics where some developers were able to meet), and this was really missed.

The meeting was attended by 25 participants representing GAP developers, package authors, users of various levels of expertise, developers of other systems such as Sage and Polymake which need to interact with GAP or be called from GAP in some calculations.

The event programme consisted of presentations, discussions, and coding sessions.

During the workshop I was posting a live stream of tweets with the hashtag #gapdays2014. 

There was a plenty of room for informal communication and working together in smaller groups. There is an intention to hold similar meetings once every six months, and to seek a variety of funding sources to enable hosting future events in different places.

The major topics covered were:

• How to write a GAP package (new tools for automation of wrapping releases, website update, regression tests for packages)
• Current state and further plans for HPC-GAP (multithreaded version of GAP)
• GAP regression tests, package update system and release management (session led by me, see slides)
• Discussions on the future of GAP
• A collection of issues contributed by participants of GAP Days 

We made important decisions about continuing to work on HPC-GAP intending to make it the next mainstream version of the system, and agreed on further actions in this direction (beta-release, converging the code of GAP4 and HPC-GAP, efforts to help package authors to migrate their packages to HPC-GAP), and about next steps to open up GAP development.

As of now, there is still no public repository and "official" public issue tracker for GAP. We hope that these will be announced soon.