Add Icinga's fork from Nagios

airtime-libretime.md

@@ -1,5 +1,5 @@
 
-The radio statiom management software [Airtime](https://en.wikipedia.org/wiki/Airtime_(software))
+The radio station management software [Airtime](https://en.wikipedia.org/wiki/Airtime_(software))
 was forked as [LibreTime](https://libretime.org/) ([archive](https://web.archive.org/web/20200108175607/https://libretime.org/)) over dissatisfaction with
 the pace of contributions being released into the former. 
 

nagios-icinga.md

@@ -0,0 +1,7 @@
+
+The [Icinga computer and network monitoring system][10] forked from [Nagios][20] in 2009. 
+
+[10]: https://en.wikipedia.org/w/index.php?title=Icinga&oldid=1074307976
+
+[20]: https://en.wikipedia.org/wiki/Nagios
+