YOUNKINT  The reply by the developer is correct regarding upgrades, although I do not agree with the, "All software companies have the exact same policy" comment. I had erroneous information regarding Linkinus' update policy. I regret the error.   
(Version 2.1)

YOUNKINT  What is it with Mac IRC client developers and greed? First Snak reneges on their promise of "free lifetime" upgrades, and now we have Linkinus charging nearly full price for minor upgrades. It's as though they *want* us to continue using open source software by shooting themselves in the feet with their pricing schemes.

This is too bad; I'd love to try Linkinus, but there is no way I will get caught up in some (evidently) annual fee just to use the latest bugfix of the software.  
(Version 2.0.3)

YOUNKINT  1.1r2 working perfectly on two 10.5.8 PPC machines.  
(Version 1.1r2)

YOUNKINT  2.0.1 crashing every time. Removed engine and ALL related ClamXav files, including cache files and prefs. Reinstalled everything. No dice. Still crashing every app start. 10.5.8 PPC QuickSilver and 10.5.8 PPC PowerBook. Both well maintained.  
(Version 2.0.1)

YOUNKINT  We've been using this on several Macs for years now. It's so valuable that it's set to automatically start on login for all our users. If your machine starts to get into trouble with an application hogging too much memory, you will see it immediately. The window can be formed to take up a tiny sliver of space, yet still give a complete graphical view of memory usage. It is particularly good for less technical users, yet shows details useful to sophisticated users as well. There seems to be no hit on system resources whatsoever.

We've never had the first problem with this little application and the price is right - free.

It's indispensable for us.  
(Version 1.5)

YOUNKINT  Exactly the same problem here. Guess I'll install manually, too.  
(Version 12.1.9)

YOUNKINT  I had the opposite problem - hangs on logout.  
(Version 2.1.4)

YOUNKINT  Before you consider installing ANY software concocted by David Watanabe on your computer, please do a decent Google search of "David Watanabe" first. Especially do this if, for some reason, you are contemplating actually sending him your hard earned money.

It will not take you long to come to a conclusion. Even a simple search here on macupdate should suffice.  
(Version 1.6v76)