From A Reyvateil's Wiki

This page lists software that ARM forum members find useful, and which other people might be interested in checking out sometime.

Graphics software and utilities

Adobe Photoshop (requires purchase)
Coral Paint Shop Pro X2 (requires purchase)
Gimp (freeware graphics editor)
Manga Studio (requires purchase)
Pixlr (free online graphics editor)
JASC Animation Shop 3 (Link Dead, ask Palsa on the forums for the download mirror) (freeware version)
PaintTool SAI (commercial, an extremely lightweight but powerful graphics editor, often considered the ultimate program for drawing linearts by professional Japanese artists)
MyPaint (A free and easy to use painting and drawing program for Windows, Linux and Mac, note: this is for artwork only and is not at all a graphics editor)
Image Resizer for Windows XP (freeware, by Microsoft, lets you resize any image just by right clicking on the image file)
Image Convert (an excellent utility for converting large numbers of image files, without losing the original's quality, freeware)
Multiple Image Resizer .NET (a great utility for resizing large numbers of images, can also add borders and overlay, freeware for noncommercial use)
VirtualDub (a useful video editor, freeware)
Media Player Classic Home Cinema (an easy to customize freeware media player, recommended for watching the extracted video and audio files,
note: separate video and audio files must have the same name and folder to play together)
RotSprite, a handy tool for resizing and rotating sprites, without creating ugly anti-aliasing effects.

Music-related software

If you often download music from the internet, especially Japanese doujin music, you might find the following software useful.

winLAME (freeware, allows converting from various audio file types into MP3 or OGG)
xrecode II (shareware, same as winLAME but supports converting from/to a lot more file types, including AAC, APE, FLAC, MP3, OGG, TAK, TTA, WAV, WMA and many more; note: demo version is fully functional except for a pop-up during startup)
Mp3tag (freeware, allows editing Tags from audio files MP3, WMA, APE, etc.)
Medieval CUE Splitter (freeware, lets you split a huge audio file that contains the entire album in it into small files of one track each, as long as you have the CUE file; note: if you download anything that has the [EAC] tag in its name then it'll surely be one multi-track file and one CUE file)
Exact Audio Copy (freeware, a simple program that can rip music CDs perfectly, even bypassing most possible copy protections)
foobar2000 (freeware, pretty much the ultimate audio player that does almost everything you can imagine of, including converting audio files, but can be quite complex to use and requires lots of plugins for additional functions)
AFSExplorer (A utility that can extract ADX audio files from AFS archives)
PES Sound File Converter (A utility that can convert ADX files, an audio format used by Gust)

Craving Explorer (freeware, Japanese only, works just like any other standard internet browser and has a built-in function that lets you download YouTube and Nico videos, converting them to WMV/AVI/MPEG and/or rip WAV/MP3 audio from them, all in just one click)
SmileDownloader (freeware, Japanese only, lets you download videos from YouTube and Nico, does a more simple and superior job at downloading than Craving Explorer, however it doesn't support on-the-fly video convert and audio rip)
FLV to AVI (freeware, can convert FLV to several different video and audio formats, it can also download and convert video's directly from YouTube)

LitLift (LitLift is a free online novel writing application built to help you research, store and organize the information you'll need to write your novel)
Writing Tablet (An easy on the eyes writing tablet, made by Palsa)