Welcome to Fawlty Language!

Fawlty Language is an IDL 7.0 (Interactive Data Language) compatible compiler (IDL is a registered trademark of ITT Visual Information Solutions). FL binaries can be freely used. Current stable version is FL 0.79a, released on Sep 3, 2009. (Changelog)



FL 0.79.27 latest development snapshot (17/Feb/2014)

FL 0.79.26 previous development snapshot (18/Nov/2013)

(Note: Sometimes FL crashes on newer systems with a 'Fatal: Cannot mix incompatible Qt library (version 0x40701) with this library (version 0x40702)' message. This is caused by some unfortunate interaction between KDE and FL's Qt libraries. One (brute force) solution is to unset all QT_* environment variables and to remove the ~/.config/Trolltech.conf file before starting FL.)

FL 0.79a stable release

FL binaries are available for the following platforms:

Example DLMs (linux only):

interface to the CXFORM coordintate transformation package:

interface to the FFMPEG library for video input/output:



FL is almost 100% compatible with IDL 6.4 or 7.0. IDL documentation is available on the net at Exelis.

Version 0.71 introduced support for dynamically loadable modules for linux. Instructions for writing DLMs can be found here.


FL is freeware, you can use it without any restriction, you can even redistribute it if you want.

IDL programs

Small IDL programs I find useful: pro


Questions, comments, bug reports can be sent to: FawltyLanguage a_t gmail d_o_t com or you can report bugs in the BitBucket issue tracker.


Lajos Földy

Last modified: 2014/February/17.