Varnish: Notes from the Architect

"I have spent many years working on the FreeBSD kernel, and only rarely did I venture into userland programming, but when I had occation to do so, I invariably found that people programmed like it was still 1975."

Watir

"Watir, pronounced water, is an open-source (BSD) family of Ruby libraries for automating web browsers. It allows you to write tests that are easy to read and maintain. It is simple and flexible."

Used by Facebook.

Graphite - Enterprise Scalable Realtime Graphing

Graphite is a highly scalable real-time graphing system. As a user, you write an application that collects numeric time-series data that you are interested in graphing, and send it to Graphite's processing backend, carbon, which stores the data in Graphite's specialized database. The data can then be visualized through Graphite's web interfaces.

Used by Etsy.

Etsy also has StatsD (blog post) which is a daemon that increments/times can be sent to, which aggregates them and sends them to Graphite.

ack 1.94 -- better than grep, a source code search tool for programmers

"ack is a tool like grep, designed for programmers with large trees of heterogeneous source code."

Unicode code converter

Convert input text to various representations and escaping levels.

Also related: Text Escaping and Unescaping in JavaScript.