11-08-2007, 01:33 PM
On the whole you don't need to maintain your mac after uninstalling software.
This is because when you install an app, its usually just a container (.app) and most of the files which are associated with that piece of software are within that container. Other files do get installed elsewhere on your mac(usually the library folder) but there harmless and don't slow down your computer because they are only used if the applications is running.
On the other hand, you do get applications which install via a .pkg installer. These apps use the .pkg installer because it needs to put more files around your HD, not just in the container. These applications require an uninstaller, most of the time its transfered into the applications folder, otherwise just check out the developers website and they should have instructions on how to uninstall the application
If you have a hardware firewall on your router than you don't need one on your mac. If you don't then you'll have to enable the firewall in System Preferences.
You don't need antimalware or antivirus software on your mac. However companies like Norton do provide of antivirus software for macs. These is so that you don't pass on windows viruses via your network or email unintentionally. The windows malware and viruses can not harm Mac OS X because there written for Windows, not for Mac OS X.
I personally just use ClamXav. It's an opensource antivirus software. I use it about once a month to ensure that I don't pass on any viruses onto my PC on my network.