I found myself wondering how to rot13 cipher text in a web browser without JavaScript or server-side interaction. I then came up with this idea, rot13 fonts. I have made rot13 equivalents for 2 DejaVu fonts, Sans and Serif. I only have the fonts use the rot13 affected characters, a-z; A-Z, Unicode ranges: U+0041-005a, U+0061-007a. This is so it would be more suitable for web use because the DejaVu fonts are 500KB+ each. The rot13 fonts are 12kb to 14kb large.
You can test these fonts to view “Uryyb Jbeyq!” (rot13 “Hello World!”) at this test page. The test page requires Firefox 3.1+ or Safari 3.1+ or for both rot13 DejaVu Sans and Serif to be installed on your computer.
The fonts are available for download here.
rot13 DejaVu Fonts being rendered in Safari 3.1.2
rot47 DejaVu fonts may be added when I get the time.