DIVA-GIS - a free computer program for mapping and geographic data analysis. This site contains a huge set of dataset with various format especially shapefile (.shp). http://www.diva-gis.org/gData
PHI-Integration - Jakarta based company providing business intelligence solutions Business Intelligence Blog - Blog with several tips on BI tool supported by PHI-Integration Pentaho Wiki (English) - A detailed technical tips on Pentaho open source BI tool
MathTools.net - Link Exchange for the Technical Computing Community