For Microsoft, the optics are a problem. The company is notorious for (justifiably) hunting down and prosecuting anyone who appropriates Microsoft intellectual property, especially as it relates to its flagship products, Windows and Office. Microsoft guards its code vehemently, and its partner contracts are ultra-stringent, but it's not the first time the gargantuan software empire has been accused of stealing from someone else's cookie jar. Just last month, a Windows 7 download tool was pulled after it was found to include unauthorized open-source code. The company is also frequently accused of aggressively using its market share muscle to crowbar its own imitative products into standard use; most famously, Internet Explorer.