Withdata Software provide some ETL (Extract-Transform-Load) tools for PostgreSQL:
TxtToPG Load TXT, CSV, TSV data to PostgreSQL
XmlToPostgres Transform XML data to PostgreSQL
JsonToPostgres Transform JSON data to PostgreSQL
XlsToPG Extract data from Excel to PostgreSQL
AccessToPostgres Extract Access data to PostgreSQL
DB2ToPostgres Extract DB2 data to PostgreSQL
MsSqlToPostgres Extract SQL Server data to PostgreSQL
MysqlToPostgres Extract MySQL data to PostgreSQL
OracleToPostgres Extract Oracle data to PostgreSQL
SqliteToPostgres Extract SQLite data to PostgreSQL
PostgreCopier Extract data from one PostgreSQL database to another