oj! Algorithms - ojAlgo - is Open Source Java code that has to do with mathematics, linear algebra and optimisation.
General information about ojAlgo is available at the project web site: http://ojalgo.org/
ojAlgo is available at The Central (Maven) Repository to be used with your favourite dependency management tool.
<dependency>
<groupId>org.ojalgo</groupId>
<artifactId>ojalgo</artifactId>
<version>46.0.0</version>
</dependency>...or download the jar from SourceForge.
User documentation wiki with examples is here at GitHub: https://github.com/optimatika/ojAlgo/wiki
Programming questions related to ojAlgo are best asked at stack overflow. Just remember to actually mention ojAlgo and tag the question using 'ojalgo' and whatever other tags you find suitable.
Bug reports and to some extent feature requests should be posted here at GitHub: https://github.com/optimatika/ojAlgo/issues (Please do not use GitHub Issues for general discussions or user support requests!)
The ojAlgo-user mailing list can be used for just about anything as long as it relates to ojAlgo. (Note that you have to be a member to post to that list!)
ojAlgo is Open Source, and you are strongly encouraged to clone or fork this repository and work directly with the source code. The source code is (part of) the documentation, and you should read it.
There's a whole separate page on contributing.