SelfControl
Description: SelfControl is a free Mac app that helps you avoid distracting websites by blocking access to them for a set period of time. It can help you stay focused and productive when you need to get work done.
Type: software
Pricing: Open Source
Wikipedia
Description: Wikipedia is a free, online encyclopedia written and maintained by a community of volunteers around the world. It contains over 50 million articles in hundreds of languages.
Type: software