This set of DOS utilities by Peter Weighill will let you convert a Commodore 64 BASIC program to IBM QBASIC and the other way around.  There are docs included in the archive.

“Turbo Rascal Syntax error - (Turbo Rascal SE, TRSE) is a complete suite (IDE, compiler, programming language, image sprite level resource editor) intended for developing games/demos for the 8-bit 6502 line of computers (C64, C128, VIC-20, NES) with a focus on the Commodore 64. With the benefits of a modern IDE (error messages, code completion, syntax highlightning etc) and a bunch of fast built-in tools, it has never been easier to program for the Commodore 64.

This is the Windows x64 version.

“Turbo Rascal Syntax error, “;” expected but “BEGIN” (Turbo Rascal SE, TRSE) is a complete suite (IDE, compiler, programming language, image sprite level resource editor) intended for developing games/demos for the 8-bit 6502 line of computers (C64, C128, VIC-20, NES, PET) with a focus on the Commodore 64. With the benefits of a modern IDE (error messages, code completion, syntax highlighting etc) and a bunch of fast built-in tools, it has never been easier to program for the Commodore 64.

This is the Windows X64 Version.

TXT64 by Sven-Olaf Scholz, released 03-1994.  This is a set of two utilities that can convert a Commodore 64 BASIC v2 program to a standard ASCII TXT file and the other way around.  Docs are included in the archive.

Generic C64 prg unpacker, original idea and code from Exomizer by Magnus Lind.

The idea is simple: to simulate the C64 memory/processor, run the program until it reaches the unpack routine, usually relocated to an address lower than $0800, then to continue execution until the Program Counter returns to a normal address usually higher than $0800. At this point, save all the memory.  I normally do this process in emulators by setting breakpoints but an automatic program that does it for me is handy.  PUCrunch and Exomizer 2.0Beta7 already have their own decrunch commands.  This program should cover those 2 and almost all the remaining ones.

Vic20PrgGen is a windows based tool for creating BASIC programs for the VIC-20 computer.

XC-BASIC is a dialect of the BASIC programming language for the Commodore-64 and xcbasic64 is a cross-compiler that compiles XC-BASIC source code to assembly source (in DASM format).

Some of the advantages of programming in XC-BASIC are:

• Cross development - use your favourite OS/editor/etc.
• Higher execution speed - no interpreter, the source can be compiled to pure machine code in two steps.
• More available memory - the program does not require the BASIC ROM to be present, which means the program code may span from $0801 to $CFFF - a total of 50K!

XC-BASIC is based on Tiny BASIC, with many differences in syntax.

See https://github.com/neilsf/XC-BASIC/ for lastest version and info.