clover DB Tool

clover.ETL and clover.GUI are ETL tools meant for developing data transformations and data integration applications. They are based on Java technology and therefore platform independent and resource-efficient. clover.ETL is an open source project, released under both LGPL and commercial license. clover.GUI is free for non-commercial purposes.


clover.ETL is an Open Source, Java based data integration framework which can be used to transform data.

Clover.ETL is released under dual-license:

Feature Highlights

  • internally represents all character data as Unicode – any character from any codepage can be represented – ASCII, LATIN, ASIAN, etc.
  • converts data from & to common character sets (ASCII, UTF-8, ISO-8859-1,ISO-8859-2, etc)
  • contains palette of more than 40 specialized transformation components
  • nativelly supports all major industry standard databases (Oracle, MS SQL, DB2, Infromix, Sybase) and several open source variants (MySQL, PostgreSQL). Other databases are supported through JDBC layer
  • reads & writes XML data/ Excel (XLS) data/ variable length data (CSV) / fix-length data and several other not so common formats (dBase/FoxPro/FlashFiler)
  • supports remote reading/writing of data through FTP/SFTP/HTTP/HTTPS protocols, also works with ZIPed & GZIPed data
  • runs on 32bit & 64bit platforms – Windows, Linux, AIX, Solaris, HP-UX, AS/400 and many others

More Features

  • data records are internally handled as a variable-length data structures – can handle very large records (theoretical limit 231)
  • fields can have default values, text formats, NULL value checkers
  • contains connectors to other systems through standard protocols: middleware – JMS, LDAP, SOAP
  • transformation of data is performed by independent components, each running as an independent thread – can utilize more than one CPU (is very scalable)
  • framework implements so called pipeline-parallelism – when data record is processed by component, it is immediately sent to the following component for additional processing.
  • contains interpreter of specialized transformation language – CTL
  • transformations (mappings) of data can be also coded directly in Java or any other scripting language
  • metadata describing structures of data (records) and transformations can be read/written from/to XML
  • works with common Source Code Management Systems – CVS, SVN, SourceSafe
  • can be easily extended by custom components

clover.ETL Overview

More detailed information on clover.ETL’s functionality can be found in the clover.ETL Overview slides (in PDF format).