WINE - An open source project which could be the tipping point for Linux
A few days back, Google did something which took everyone by surprise. It released Picasa - a very popular and advanced image archiving tool that also includes a lot of photo manipulation features - for Linux, which till now only worked in Windows . But what was cleverly shielded from the average user was that Picasa released for Linux is the very same Picasa for windows but running on top of Wine - an Open Source implementation of the Windows API on top of X and Unix. In fact any body who uses Picasa will not be aware that he/she is running a windows software in Linux unless it is pointed out.
Wine has been around for a long time now and there are even companies which operate for profit such as Codeweavers who sell a fine tuned version of wine to allow people to run Windows software on Linux.