Miningco is an automatic data-mining (can be used for business intelligence) tool. It can analyse a table in a database and then automatically give you a list of remarkable rules to which your data complies. It can find for patterns on what columns they depend. From version 2.0 it can also group ranges of values into 1 rule.
Example scripts have been added for datamining on Nagios and Apache logging.
An announcement- and discussion mailinglist has been started.
Send an e-mail to email@example.com with in the subject 'subscribe miningco' to subscribe. The archive can be found here.
2.5 Improved clustering: no more fuzzy ranges as well as better combining ranges. 2.2 The non-clustering part was broken, fixed 2.1 Clustering did not always work, fixed 2.0 Miningco can now cluster groups of values into 1 rule 1.3 Added a script for importing syslog logfiles 1.2 Added a web-interface for easy navigating through the results 1.1 Added import script for Apache logging 1.0 Initial release
Links to other free datamining software
Yale: YALE is an environment for machine learning experiments and data mining.
The R Project: R is a free software environment for statistical computing and graphics.
Wikipedia has a great explanation on data-mining with a few pointers to more information.