In the animal world, when the biggest lion begins to age and some of the younger males sense that the leader is weakening, they prepare to try to take his spot.

In the world of operating systems, the longtime king, Microsoft, continues to have other OS options nipping at its heels. Recent announcements show that Google and Apple are trying to strengthen their positions, just in time for the widely anticipated upcoming release of Windows 8, which should be sometime late in 2012.

Google has recently purchased Motorola, through which it could strengthen Android's share in the market. Apple obviously has its popular smartphone and tablet platforms, and it has recently announced plans to offer a new Mac OS, currently called Mountain Lion, that will ship this summer.

Obviously, the upcoming Windows 8 release and Mountain Lion will be aimed at different types of computer systems, but it's probable that Mountain Lion will draw some of the media attention away from Windows 8's release. And, if Mountain Lion can continue to allow Apple users to further integrate their iPad, iPod and Apple smartphones with their Mac computers, its popularity will continue to challenge Windows.

As mobile devices become a bigger part of the computing world, it's easy to imagine Windows' stranglehold on the operating system market showing further cracks. Although Windows has long been the dominating OS with network computers, desktop computers and laptops, the greater impact of mobile devices on the computing market is showing.

It's already been proven that operating systems like Android, Blackberry and Apple's iOS are popular among smartphones, where a system like Windows Mobile hasn't been able to dominate like it has among computers.

Android tablets, Blackberry tablets and iPads are challenging Windows in the world of tablet computing, too.

HP also may try to join the fray, as it has recently chosen to offer its webOS as an open source project. Certainly, if as rumored by HP's Meg Whitman, Google chose to remove Android from the open source pool and only offer it on Motorola brand products, the need for another open source operating system in the mobile world would be appealing.

However, the downside is that open source proponents would basically be starting from scratch again, after all of the work put into Android. Ultimately, it really seems unlikely that Google would take Android in this direction. Android is in use with so many different pieces of hardware now, both with tablets and smartphones, that it could spark some significant legal problems for Google to try to remove it from any non-Motorola devices. While this may be a direction that Google takes Android in the future, it certainly won't be happening any time soon.

Then there's iOS from Apple and the Blackberry platform, both of which also have a significant market share. It seems unlikely that a platform like webOS would have much of a chance of being able to challenge Android, Blackberry or iOS in the mobile market, as those are simply superior products.

Microsoft is taking hits in some other areas, too. Cisco is protesting Microsoft's recent $8.5 billion acquisition of Skype, which is an Internet-based calling service that includes real-time video with the audio. The European Commission has approved the merger of Microsoft and Skype, but Cisco would like to see Microsoft work more closely with open source options for video calls, with the idea of making the entire process of video calling as easy as sending an e-mail. It seems pretty unlikely that Cisco's appeal will be approved, as the European Commission already has approved the deal, but this does represent another major potential headache for Microsoft as it tries to strengthen its position among mobile users.

Although all of the different operating systems may seem a bit confusing, it shows that the competition in this arena has never been greater. Microsoft has been the dominant force in operating systems with its various Windows versions for a long time, but Google and Apple have found ways to challenge Windows and Microsoft on a variety of products. The other lions are circling.