Shoroo_Lupin
The first link I wouldn't count as evidence because, although it's a well written article, it is not neutral. It is biased in that they are attempting to convince the reader that Microsoft did in fact, blatently steal from Apple.
This line alone makes the article unreliable: "This became Windows 1.0, and evolved into the Windows we know and hate today."
No cigar for you! Be careful when reading this man, he notes that Billy G *stole the ideas and design* not the actual code. That'd be futile, at best, since Windows was designed to run on DOS.
Funny though, DOS wasn't a "ripoff", they purchased that from Paul Allen, though QDOS was a quick-n-dirty CP/M based 'operating system'.
If you compare Windows 3-ish to other GUIs at the time though, things really become humorous, by the launch of 3.1 MS was competing with NeXTStep, AmigaOS, and even BeOS -- not to mention almost a dozen other competitiors along with Mac OS. It's quite amazing they actually "won", but much of that they owe to the MS+IBM OS/2 venture.