Texturize is a text filter that modifies posted text or comments to present a more readable and visually attractive output.
While it creates aesthetically pleasant text, it might create difficulties when posting, for instance, code examples in a programming language. In such situations modification of the text is not desirable because it might create syntactically incorrect code.
Texturize is enabled by default.
A few examples (please add more if you know of them):
"quoted text" becomes “quoted text” 'quoted text' becomes ’quoted text’ --- becomes — -- becomes – ... becomes … (c) becomes © (r) becomes ® (tm) becomes ™ '' becomes ” `` becomes “ president's becomes president’s presidents' becomes presidents’ 12' becomes 12′ 12" becomes 12″ 2x4 becomes 2×4
Eventually, this will hopefully be an easily accessible option on a per post/comment basis.
Alex King's wp-unformatted plugin "...allows you to add custom fields to a post to disable auto-formatting and/or auto-smart-quote conversion." Untested, but appears to be an applicable solution.
Reference:WordPress Wiki - Plugin/API
Other engines? Textile, etc.
texturize web interface.