lighttpd vs Pow: What are the differences?

Developers describe lighttpd as "A secure, fast, compliant, and very flexible web-server that has been optimized for high-performance environments". lighttpd has a very low memory footprint compared to other webservers and takes care of cpu-load. Its advanced feature-set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) make lighttpd the perfect webserver-software for every server that suffers load problems. On the other hand, Pow is detailed as "Zero-configuration Rack server for Mac OS X". Pow is a zero-configuration Rack server for Mac OS X. It makes developing Rails and Rack applications as frictionless as possible. You can install it in ten seconds and have your first app up and running in under a minute. No mucking around with /etc/hosts, no compiling Apache modules, no editing configuration files or installing preference panes. And running multiple apps with multiple versions of Ruby is trivial.

lighttpd and Pow belong to "Web Servers" category of the tech stack.

Pow is an open source tool with 3.47K GitHub stars and 259 GitHub forks. Here's a link to Pow's open source repository on GitHub.