Letterpond requires a few things in order to function properly. Judging from the fact you're reading this, I'd say you have the essentials sorted, but I'll list them all here just in case:
- A webserver conforming to the CGI/1.1 specification (most do so well enough for Letterpond to run).
- PHP 5.1 or higher, with the following extensions enabled. Some of these can be omitted if you aren't using modules which require them, but most can't.
- DOM (Note that this is not the same thing as PHP 4's DOM XML)
- A writeable cache directory - by default this is the 'cache' subdirectory of your letterpond installation, but you can move it elsewhere by defining LP_CACHE.
- A supported database server - currently this means either PostgreSQL or MySQL.
In addition to the above, you may also wish to have the following:
- URL rewriting (usually mod_rewrite) to enable 'fancy' URLs
- X-Sendfile support (decreases load on the server by allowing it to stream static files directly)
- A POSIX-compliant server OS such as Linux or BSD (because they're just so much nicer to admin)