To join the IRC through a desktop client, you can follow the following example: I have used XChat for Ubuntu in this example but the process should be similar for other clients too.
1) After installing the client, choose a nick and other name choices which will be displayed when you post chat messages. 2) Choose OFTC as the network. PublicLab channel is hosted on OFTC network.
3) Under Join this channel enter: #publiclab
The next screen should be the publiclab live IRC.
People unfamiliar with using Desktop client can participate in IRC at http://publiclab.org/chat