A proprietary fourth generation computer language (4gl) used primarily in business applications development in GUI mode, ChUI mode, and for the web, via the WebSpeed application server. It is created by Progress Software Corporation to provide interaction with their Progress RDBMS product.

The primary advantages of a language like Progress 4gl is its tight integration with the database, and easy-to-use language constructs. For instance:

DEFINE VAR i AS INTEGER NO-UNDO.
FOR EACH customer 
 WHERE customer.state = "TX"
 NO-LOCK:
    i = i + 1.
    DISPLAY customer WITH SIDE-LABELS 2 COLS.
END.
DISPLAY i LABEL "Texas customers".

Progress is a compiled / interpreted language, meaning that it must always run through an interpreter. However, it can be "compiled" into .r files, which speed up the execution and obfuscate the source code