2006-04-17
Haskell Application Server - HAppS
Haskell gets more interesting every day. In the Haskell Weekly News was an announcement of HAppS, a Haskell Application Server. A nice list of features:
- HTTP Application Server
- Performs better than Apache/PHP in our informal benchmarks (thanks to FastPackedString), handles serving both large (video) files and lazy (javascript) streaming, supports HTTP-Auth, and more.
- Mail delivery agent with integrated DNS resolver
- Stop worrying about making sure a separate local mail server or DNS is up and running to delivery your mail. HAppS takes care of making sure your mail is delivered as long as your application itself is running and makes sure no outbound mail is lost even with unplanned restarts.
- XML and XSLT
- Separate application logic from presentation using XML/XSLT. With HAppS, you can have your application output XML (via HTTP or SMTP) and handle style/presentation via separate XSLT files at runtime. HAppS takes care of doing server side XSLT for outbound mail and HTTP user-agents that don't support it client side.
- SMTP Server
- Handle incoming email in your application without worrying about .procmail or other user level inbound mail configuration hackery. Just have the HAppS.SMTP listen on port 25 or have the system mail server SMTP forward mail for your app to some internal port.
- Monadic ACID transaction service
- Write apps as a set of simple state transformers. MACID write-ahead logging and checkpointing make it easy for you to guarantee application integrity in the face of unplanned outages. MACID even guarantees that your side effects will be executed at-least-once if they can complete within a timelimit you define.
- Session Service
- Define bits of per-user application state that automatically expire after time limits you define. No more manual housekeeping of session data!
- (Experimental) Table and Index
- Do relational operations safely on in memory Haskell Data.Set(s) rather than dealing with an external SQL relational database. Define custom indices for your Haskell datatypes (e.g. geographic/geometric types). Use in combination with MACID for a robust relational DBMS customized for your application.
