Programming

All About Your... Help Files
Help system for Commodore programmers by Ninja. Available in ASCII and HTML for the C64, 1541, and 1581.
http://www.the-dreams.de/aay.html

Assemble IT!
Large tutorial on the assembly programming side of the C64 scene.
http://www.redesign.sk/tnd64/assemble_it.html

C64 BASIC/Kernal ROM Disassemblies
Lists the Commodore 64 assembly source code for BASIC (A000-BFFF) and Kernal (E000-FFFF) operating system.
http://www.unusedino.de/ec64/technical/misc/c64/romlisting.html

C64 Codebase Wiki
Various articles related to C64 coding. Source code, tutorials, clever tricks and hardware quirks.
http://www.codebase64.org/

Commodore Languages List
List of programming languages available for Commodore 8-bit computers. Some languages have dozens of entries.
http://www.npsnet.com/danf/cbm/languages.html

The Fridge
Source code, tools and technical information for Commodore and 6502 programmers.
http://www.ffd2.com/fridge/

Hex Files
Beginners' course in Commodore 64 machine code and graphics handling originally written for the magazine Commodore Zone.
http://www.oldschool-gaming.com/c64_hex_files.php

An Introduction to Programming C-64 Demos
Linus Åkerlund's tutorial about writing demos with assembly language.
http://www.antimon.org/code/Linus/

The Scratchpad
Various BASIC and machine language programming projects for the Commodore 64.
http://www.white-flame.com/scratch/scratch.html