Security firms are always keen to release new versions of their products, and the unveiling of a new operating system is as good a reason as any. Mac users who jumped on OS X Lion the moment it was released have found that there are a number of applications that do not work correctly, or at all, and this can be a serious issue when it comes to security software. Symantec has just released two Lion compatible security products in the form of beta versions of Norton Internet Security 5 and Norton AntiVirus 12 for Mac.

Lion support is one of the main reasons for the existence of both of these new versions, but there are also a number of changes and additions. Performance improvements are always something of a subjective claim, but the new Norton software takes advantages of some of Lion's new underlying features to help speed things up.

Any PC users who have worked with the Windows versions of these two applications will notice that the interfaces have received a refresh, but this is far from being the most important change. One of the ways in which performance has been improved is by changing how the software interacts with removable media. When you plug in a USB drive, or connect other removable media, it will not be scanned in its entirety -- instead, files will be scanned as and when you access them.

The way in which general system scans work has also changed. Rather than relying on a scanning schedule to check for signs of infection, scans are performed during idle time. Faster installation of definition updates means that protection against the latest threats is available faster than ever. It is worth noting that these are both beta products, and while they seem generally stable, user experience will differ from one system to another -- if your Mac is mission critical, it might be a good idea to hold off installing for the time being.

You can find out more and download copies of the two beta products by paying a visit to the Norton Internet Security 5 and Norton AntiVirus 12 for Mac review pages. Note that both betas offer a 14 day license. Simply click "renew" to extend this license after 14 days. The beta builds will expire October 31 2011.