Pentaho offers comprehensive data integration and analytics platform.
ETL engine based on Groovy
NBi is a testing framework (add-on to NUnit)
World's first open source data quality & data preparation project
Design, automate, operate and publish data pipelines at scale
Data quality analysis, profiling, cleansing, duplicate detection +more
Adhoc Data Exploration - Live & Easy
sparse and dense matrix, linear algebra, visualization, big data
Open source Extract Transform Load engine written in Java