Services: GNU/Social and Mastodon instances

services.mdwn

@@ -96,7 +96,7 @@ Social media
 * [Diaspora](https://github.com/diaspora/diaspora).
 * [buddycloud](http://buddycloud.com/) ([desenvolvimento](https://buddycloud.org) / [pacote](http://packages.debian.org/sid/buddycloud-server)).
 * [BuddyPress](http://wp-brasil.org/buddypress).
-* [GNU social and GNU FM](https://gnu.io/).
+* [GNU social and GNU FM](https://gnu.io/) ([public instances](http://www.fediverse.org/)).
 * [qvitter · GitHub](https://github.com/hannesmannerheim/qvitter).
 * [kune.cc](http://kune.cc/).
 * [Tent](http://tent.io).
@@ -108,7 +108,7 @@ Social media
 * [Incoma](https://github.com/Incoma/Incoma).
 * [Sneer](https://github.com/klauswuestefeld/sneer).
 * [Noosfero](http://noosfero.org/).
-* [Mastodon](https://mastodon.social).
+* [Mastodon](https://mastodon.social) ([public instances](https://instances.mastodon.xyz/))..
 * Democracia: [Liquid Democracy](https://wiki.piratenpartei.de/Liquid_Democracy) / [Liquid Feedback](http://liquidfeedback.org).
 * [Briar](http://briar.sourceforge.net).
 * [Twister](http://twister.net.co/).