[r0m4n0]

Went through an acquisition with Vmware... they converted the stock options to Vmware options that vested at the same rate and were worth the exact same based upon the acquisition price. If they had already vested, they just paid you out. This may depend on the deal though.

[rongenre]

I've been through two acquisitions and part of the deal terms if the valuation of the acquiree's shares (which the cap table and liquidation preferences have a huge effect on).

First time my options were converted to options in the acquirer's company.

Second time they turned into RSU's.