Open Source Math
An anonymous reader writes "The American Mathematical society has an opinion piece about open source software vs propietary software used in mathematics. From the article : "Increasingly, proprietary software and the algorithms used are an essential part of mathematical proofs. To quote J. Neubüser, 'with this situation two of the most basic rules of conduct in mathematics are violated: In mathematics information is passed on free of charge and everything is laid open for checking.'""
I have seen from personal experience, how a compiler error (some sort of incorrect optimization) led to a subtle difference in the results of a simple classification task.
The insidious thing about that particular result was that it looked very similar to the correct. In fact the difference would not have been found if two people did not run different versions of code independently (and more or less coincidentally) arriving to slightly different error rates.