"Mostly I use the O2 as an X terminal, however, running my apps on Linux and displaying remotely"

Jamie Zawinski is referring to the use of a computer system referred to as an X terminal. An X terminal is a computer system that is used to from another location gain access to and display screen applications working on another computer system, typically a Linux system. In this case, Jamie Zawinski is using the O2 computer system as an X terminal to gain access to and screen applications operating on a Linux system. This allows him to gain access to and usage applications on the Linux system without needing to install them on the O2 system. By utilizing the O2 as an X terminal, Jamie Zawinski is able to gain access to and usage applications on the Linux system without needing to install them on the O2 system. This is a hassle-free and efficient method to access and usage applications on a remote system without needing to install them on the local system.