Most outline fonts are often drawn blurry or weak on Windows if they don't have any bitmaps. It's quite sure that ClearType technology has improved its rendering quality and alphabets get definetely clearer than Mac OS X, however, some complicated glyphs such as Japanese kanjis look somewhat distorted by contrast. The new japanese font Meiryo, shipped with Windows Vista, seems much better and still clear even in smaller point sizes, but this is not a fundamental solution at all, because the other outline fonts still look quite poor only on Windows. It can be said that the font is one of the most important and hottest elements on GUI design. As a Windows user, I'm really annoyed at the fact that the rival OS has better font rasterizer than that of Windows which has the largest market share in the world.
gdi++.dll provides better quality by overriding some API functions of gdi32.dll, such as TextOut(). When the function is called, it draws the text up to 4 times larger to a back buffer temporally and tranfers it to a display after resampling with interpolation. This behaiviour might be similar to the shareware called SmoothType, which is written for old Macintosh. The screenshot is an example which shows M+2P+IPAG in 9 points. The result on the right look less distorted or blurred, so you might feel it's comfortable to read compared to the left original one.
On the latest version of gdi++.dll, you don't have to use a binary file editor. Just drag and drop your favourite application to gdi++.exe, and then the requests for gdi32.dll are going to be passed to gdi++.dll automatically. For example, it goes like the screenshot when you drag and drop "Opera.exe", which is in the installed directory of the web browser, Opera. You must be surprise that this is just working on Windows.
Plus, of course you can apply this technology to your own application. After building your program using gdi32.dll normally, drag and drop the EXE as mentioned above and the font quality will get better. Perhaps this is suiutable for some hentai visual novel games or text viewers.
gdi++.dll is a open-sourced (not in the essential meaning of OSS) software, built with highly-dependable Microsoft Visual C++ 6.0 SP6. You can redestribute it without permission. Any feedbacks are really appreciated.
Now, We're mainly discussing about this software at the relevant thread on 2ch in Japanese, the largest and geekiest Internet forum in Japan. If you have a say, please post messages on it, or if you want to make a contact with me personally, write to the following address.