Google Summer of Code 2011: A summary

Google summer of a code is an annual programme where Google pays students to work on open source projects in the summer months. The students have one or more mentors from the project who help them get started and function as a contact point for the developer community.

In 2008 I did a Google Summer of Code project for the Kate text editor where I wrote a Vi Input Mode – making it possible to use Kate in a modal, Vi[m]-like manner. The project was successful and I continued to maintain this code and added more features over the years. This summer I took the step of signing up as a mentor myself and put out a project proposal for further improving the Vi Mode in Kate and adding a good unit test framework for the code. To my surprise – and delight! – many students were interested in the project and we ended up getting quite a few applications from students wanting to work on “my” project. In the end the Russian computer science student  Святослав Кузьмич (Svyatoslav Kuzmich) from Moscow Institute of Physics and Technology was chosen.

The Kate Editor

The Kate Editor

Over the summer he wrote a test framework for the Vi Mode and wrote test for the functionality already present. Having an easy way of adding tests for the Vi mode had been on my wish list for a long time and it was really nice to see it implemented. It did not take long for the new test system to show its value: Svyatoslav found some corner case bugs that had probably been in the code for a long time and fixed them. A short overview of the new test framework can be found at the Kate blog: Kate Vi Mode Test Suite.

Svyatoslav also made many more visible improvements to the Vi Mode such as jump lists (making it possible to jump back/forward to where you were in the text), making it possible to control sub windows with the keyboard, many new command line mode commands and much more. An overview can be found in his blog post at

For me personally it was an interesting experience to act as a mentor for another programmer. My function also changed as the project progressed. In the beginning I tried to give Svyatoslav an overview of the current code and answer some questions as they came up. The programming work itself was rarely a theme – Svyatoslav was already a really good coder and generally just needed to be pointed in the right direction or – even more commonly – just get a confirming nod that his suggested solution sounded good. Since I had a few years to think about many of the features he wanted to implement I also had a few “that does sound like a good idea, but…” often learned the hard way. :-)

In the end the project turned out very well and the users will get many new features – some of which have been wished for for years.

As a wrap-up of Google Summer of Code 2011 I am going to San Francisco next week to take part in the GSoC 2011 mentor summit where mentors from the organizations taking part in the Summer of Code meet to exchange experiences and discuss future directions for the programme. I am really looking forward to that! :-)