Browser compatibility continues to be something we consider every time we put up a new design or make edits to a website. Thankfully, this isn’t as big an issue as it was a few years ago, thanks in part to browsers supporting the same fundamental technologies and to web development tools alerting us of potential incompatibilities as we work on the sites.

When testing our designs in different browsers, I turn to NetMarketshare to see which browsers are trending. I find this helpful for not only determining on which browsers we should focus, but also which ones we should start watching out for.

For March 2011, the top five browsers (as reported by NetMarketshare) were:

1. Microsoft Internet Explorer – 55.92% (slowly losing ground)
2. Firefox – 21.80% (mostly remaining flat)
3. Chrome – 11.57% (gaining ground)
4. Safari – 6.61% (slowly gaining ground)
5. Opera – 2.15% (remaining flat)

The other browsers in the top 10–including Opera Mini, Netscape, and Mozilla–accounted for less than 2% of total browser market share.

It’s also helpful to look at operating systems–specifically, mobile devices.

1. Windows – 89.58% (89.69)
2. Mac – 5.25% (5.25%)
3. iOS – 1.87% (1.81%)
4. JavaME – 0.98 (1.04)
5. Linux – 0.96% (0.92%)
6. Android – 0.56% (0.52%)
7. Symbian – 0.34% (0.35%)
8. BlackBerry – 0.13% (0.12%)
9. Windows Mobile – 0.03% (0.03%)
10. Playstation – 0.02% (0.02%)

Windows continues to account for the majority, of course, but it’s interesting to note the continued rise of iOS (Apple’s operating system for the iPhone, iPod touch and iPad), which is now even beating out Linux! Android continues to slowly gain some ground as well, while Symbian, BlackBerry and Windows Mobile all remain flat. Still, despite the relative small marketshare for portable devices, developing mobile versions of websites continues to become more important as these numbers continue to rise.