Tippy.js - lightweight, pure JavaScript tooltip library
Sysdig - open source, system-level exploration: capture system state and activity from a running Linux instance, then save, filter and analyze. Kind of strace + tcpdump + lsof + awesome sauce. With a little Lua cherry on top.
Tippy.js - lightweight, pure JavaScript tooltip library
DO_Snapshot - command-line snapshot maker for your DigitalOcean droplets.
MetaBase is the easy, open source way for everyone in your company to ask questions and learn from data.
MailHog - Web and API based SMTP testing, inspired by MailCatcher
Localstack - a fully functional local AWS cloud stack. Develop and test your cloud apps offline!