One way of building iGate is to connect a TNC between the receiver and PC. Since I wanted to set up a minimum hardware iGate and since I didn’t have a suitable TNC, I use a SW called soundmodem between the radio and PC’s soundcard.
Xastir is a versatile APRS client which I have configured to send my location to APRS-IS server network. Xastir is in Ubuntu repository so it’s easy to install either by using synaptic or by typing “sudo apt-get install xastir” on terminal.
Ubuntu releases 2 new versions every year, in April and October. About one and an half year ago I got fed up and decided to update only when a long term support version is released. In synaptic you can choose to get notifications only for LTS versions. Here’s the Ubuntu release timeline.