Haserl is a small program that uses shell or Lua script to create cgi web scripts. It is intended for environments where PHP or ruby are too big. It was written for Linux, but is known to run on FreeBSD. A typical use is to run cgi scripts in an embedded environment, using a small web server, such as mini-httpd, lighty, or the server built into busybox.

he haserl binary typically compiles to less than 20KB (stripped). The lua language adds less than 150K if linked in statically. Parses like other scripting languages: Anything that is not enclosed in <% ... %> tags is sent verbatim to the client. Form elements sent from the client are automatically parsed and placed into environment variables. The script can then reference the variables without any extra work. Mime data sent via the enctype="multipart/form-data" method is transparently decoded. This method is used when uploading files from the client. Attempts to drop its privileges to the uid/gid of the owner of the script for security.