Onno Chess Software : About

Who wrote Onno?

The Chess Engine "Onno" was written by Onno Garms.

When did Onno start?

Onno started as a spare time project in the summer of 2006. The first public release, version 1-0-0, was released in May 2009.

Where does the name come from?

My first name which is also the engine name comes from Friesland, but I don't. My parents and I thought it was the Frisian version "Arnold" (as in "Arnold Schwarzenegger"), but Wikipedia gives other possible etymologies.

In which language was Onno written?

Onno was written in C++. I made use of most C++ constructs at least in the sections that are not critical for the performance, so it's really C++ and not just what I call C+.

Was any third party code used in Onno?

Onno uses the STL, the boost libraries and the Mersenne Twister random generator.

Versions 1-1-0 and later use the tablebase access code by Eugene Nalimov and Andrew Kadatch plus a file based on lock.h from Crafty.

How does Onno work?

Most of Onno's algorithms are well known. If you want to learn about chess programming, visit some of these or these pages. Onno uses bitboards with magic multiplication, alpha-beta-search with windowing and scout search, null move pruning, history pruning, and late move reductions. The parallelization is based on the Young Brothers Wait Concept.