Squeak
A free Smalltalk system.

Java
Perhaps the definitive source for using Java and related applications under RISC OS.

32-bit RISC OS
Developer support for the Iyonix PC from Castle Technology.

Arm Sort
Module which provides BASIC programmers with fast facilities for sorting arrays.

Python
Binaries of version 2.3, RISC OS specific modules, and a "Getting started" guide.

C Programming Information
Guide to C programming on RISC OS. Documentation and tutorials, compilers, libraries, and downloads.

AcornCD
A CDDB server for RISC OS. Includes programming specifications and demonstration program.

Awk
RISC OS port of the Mawk interpreter.

Lua
Two implementations of Lua for RISC OS. Downloads, documentation, and examples.

PHP
RISC OS port of the HTML-embedded scripting language. Interpreter and StrongHelp manual.

ArmBob
Interpreter for a variant of Bob, a small object-oriented programming language. Documentation, examples, and source.

Fortran Friends
A user group for Fortran on RISC OS. News, information on compilers and libraries, and list of products.

Basalt
Extends BASIC with new keywords. List of features, manual, and downloads.

Basil
Shares BASIC libraries between programs. Overview, manual, and download.

PERL
Port of Practical Extraction and Report Language.

Gofer
RISC OS port of the Gofer interpreter for Haskell, a lazy functional language.

Hugs
RISC OS port of the Hugs interpreter for Haskell, a lazy functional language.