On Wednesday, Microsoft delivered its long-delayed Zune 1.3 software, which includes updates for both the Zune portable media player and its PC-based software. Aside from releasing this software, Microsoft also noted that the Zune continues to be the second best-selling hard disk-based portable media player in the market, following the dominant iPod.

A minor update, Zune 1.3 is aimed at improving sync functionality, FM tuner integration, and music playback, according to Microsoft. Specifically, the update adds performance improvements and prevents the FM tuner feature from draining the battery while the Zune is in sleep mode. Zune users will automatically receive the updates when they launch the Zune software or sync with their device.

Microsoft also noted this week that Zune is maintaining its number two position in the hard disk-based MP3 player market. This data, which comes from market researchers at NPD, shows that Zune accounted for 8.7 percent of the market in February. It's unclear if this number represents retail sales only, or whether it is worldwide or US-only.

"We're pleased that Zune has been able to have such a significant impact on the market in such a relatively short time and look forward to the interest that our next wave of advertising is sure to drive in the coming month," says Zune Marketing Director Jason Reindorp. Of course, Zune is fighting an uphill battle against Apple, which commands most of the remaining 90+ percent of the market in which Zune now competes. Microsoft is expected to release new Zune models in various form factors as well as further software updates over the next year.