This information on using ScoutLink from a mac has been taken from "Zerofon's Amazing Guide for Mac-user to JOTI and Scoutlink!" whitch you can find at http://www.zerofon.co.nr/.
For alternative clients or extra details visit http://www.zerofon.co.nr or see the salient points below.

Recently updated, Colloquy is probably the simplest of my recommended clients to set-up and run. The simple interface may lack the single window of the others listed here (although you can close all the windows you are not using such as connections) but it is no less powerful. Extendable with AppleScript and plug-ins, and customisable with styles, a huge collection of all these is available from the Colloquy website. All conversations can be highlighted and bookmarked and are therefore searchable to a very high degree. They can also be transcripted and saved, you can even use a unique feature called smart transcripts that is highly customisable and can be pre-set to alert you when any particular phrase, event or even a series or combination of these occurs whilst within channels. The Colloquy website is here, and my set-up guide is here. Of all the clients listed here, Colloquy has the development and is kept up to date. There is also a version available for the iPhone.
On launch, Colloquy will bring up its Connections window:

Click the ‘New’ button at the top left to open ‘New Connection’.

Now click on the blue arrow button next to ‘Details’ to fully open the window:

If you haven’t already registered your nickname with Nickserv, do so now by entering the command:
/nickserv register YOURPASSWORD YOUREMAIL.
To avoid having to identify yourself to Nickserv every time you connect, follow this further step. With the chosen server highlighted in the Connections window, click the ‘Info’ button - this brings up a further window as below.

In the ‘Password’ field of the ‘General’ pane, enter your Nickserv password.
Lastly for JOTI, don’t forget to register your nickname at http://www.jotijota.org/community/ to ensure you can send and receive validation cards.