DBeaver is free universal SQL client/database tool for developers and database administrators. It can work with any database server which has JDBC driver. It supports pluggable extensions. Version 3.x has special extensions for: MySQL, Oracle, DB2, PostgreSQL, SQL Server, Sybase, Exasol, Informix, Teradata, Vertica, Netezza, Phoenix, Firebird, Derby, H2, WMI, Cassandra, MongoDB, Redis, Snowflake.
Features: Database metadata browser, metadata editor (tables, columns, keys, indexes), SQL statements/scripts execution, SQL highlighting, autocompletion, hyperlinks in SQL editor, Result set/table view/edit/search, BLOB/CLOB view/edit support, scrollable resultsets, data (tables, query results) export and import, transactions management, database search, ER diagrams, automatic drivers download, etc.
Standalone version download available on http://dbeaver.jkiss.org/download/
Source code: https://github.com/dbeaver/dbeaver