Yes, Netscape "open sourced" their code before the AOL buy, but as a desperation measure on their way to the scrap yard - a vain hope for get free development work since they could no longer afford it themselves.

The Mozilla team judged Netsape's code too bad to salvage and pretty much started over, which is why it's taken so long.

If Andresen could have keept his mouth shut, Netscape might have lived, but seeing the lion asleep, the monkey yanked it's tail, with predictable results.