Progress so far

TreeTapper is hosted by NESCent and uses a PostgreSQL database as a backend, an assortment of PHP scripts for generating pages, and the Yahoo User Interface Library (YUI) for a front end. Reasons for these decisions:

• NESCent hosting: Free, stable, well-supported, appropriate for the project, and allows things like use of mod_rewrite to make creating RESTful site easier.
  
• Postgres: NESCent supports this rather than MySQL; triggers and views will be useful (though now also allowed in MySQL). I had thought about using arrays for some fields (a Postgres-only feature), such as when a particular bit of software can read multiple tree formats, but will instead use additional tables, following recommendations from NESCent's IT staff.
• PHP scripts: I had looked into using Ruby on Rails, CakePHP, or other frameworks for development, but there seemed to be a lot of overhead in learning them for the benefit I'd receive.
  
• YUI: This is one of the many libraries for Ajax development. YUI is feature-rich and has both great documentation (with many examples) and an active user forum, both important for me.

I've also created the database schema and a way to securely log in (using PHP sessions). Next, I'm adding the ability to store and look up references in Connotea (using a Perl API) and other reference-parsing tools so that I can start adding papers to the database; I'll also create forms for adding methods and software and start actually adding information.