Gitter - real-time chat integrated with GitHub. Like IRC - but modern :) Issues, markdown, code highlight and external integrations
Using Elementary OS 0.3 Freya daily build for two days. Not ideally stable (it is not even beta), but beautiful :) Btw. Beta status could be tracked in http://isfreyareleasedyet.com/.
Gitter - real-time chat integrated with GitHub. Like IRC - but modern :) Issues, markdown, code highlight and external integrations
Pageres - NodeJS tool to create a website screenshots in different resolutions (for responsive layout testing). Based on PhantomJS.
Elastic Search 1.0 is released!
Great collection of HTML/CSS only animations CSS A/Z
Leaflet Heatmap visualization plugin. Works very fast and responsive on big amount of points. Demo