• The easiest and cheaper way to acquire a serial port adapter is to build one.
  • ExtFriend is an implementation of the serial port adapter for the Raspberry Pi Pico, allowing one to be built for under 20 USD using an HDMI connector in place of the official EXT connector. Port Zero wrote a tutorial on how to do so (in Japanese).
• RetroOnyx sells ready-built USB link cables for 85 USD each.

If you own a licensed WonderWitch cartridge, you may download the FreyaOS 1.2.0 update package on Qute's WonderWitch Player website. While the site is intended for WonderWitch Player owners only, this file also was available for registered WonderWitch owners via an FTP server; however, that server is no longer online.

Typically, these libraries were available on the WonderWitch and WonderWitch Player CD-ROMs, as well as on the WonderWitch registered user portal. While permission has been granted to redistribute them as part of games, many older releases do not include these libraries. Links to online copies of commonly required libraries are provided below:

• sound.il (1.02): http://wwgp.qute.co.jp/2002/entry/00058/rave/sound102.il
• bmpsaver.il (2.01): This library is used for development purposes only, but some games may accidentally depend on it. While the binary is not available online, source code can be used to compile it and is provided here http://wwgp.qute.co.jp/2001/entry/00152/BMPSaverWWGP. Note that the latest version of the library is 2.03.

The following compilers had official libraries provided for them by Qute Corporation on the WonderWitch CD:

• LSI C-86 3.5.12 for WonderWitch - developed by LSI JAPAN CO., LTD; bundled on the CD, the default and most popular choice. Note that the WonderWitch package only comes with non-commercial use rights for this compiler.
• Turbo C 2.01 - developed by Borland International, Inc.; bundled on the CD.
• Digital Mars C++ - later versions of the CD came with start-up and build files for this compiler.

The following compilers were adapted for the community for use with Qute Corporation's official WonderWitch libraries:

• Visual C++ 1.5

The following compilers can be used with unofficial, community-made libraries:

• GCC 6.3.0 / Wonderful