Prometheus : Prometheus is an open-source systems monitoring and alerting toolkit originally built at SoundCloud. Prometheus's main features are:
a multi-dimensio...
Zulip : Powerful slack-like open source group chat
Lemmy : Lemmy is a selfhosted social link aggregation and discussion platform. It is completely free and open, and not controlled by any company. This means t...
ntfy : Send push notifications to your phone or desktop using PUT/POST
LGTM.in : Looks good to me (LGTM) is the most popular comment on Github, perhaps. But LGTM is boring. So we spice it up with some images.
A lightweight, open source, tracking-free comment engine alternative to Disqus.