I didn’t really read your earlier Linux thread, but testing platforms really depend on the type of fonts your making (any complex script fonts?) and the type of customer (regualr user, graphic designer, ISV, OEM…)

I thought that the FontLab presentation by Phinney and Twardoch at Typecon ‘06 was very interesting. They spent some time describing the process for naming font families so that they appear as expected in Windows applications. The reason I mention this, is because style-linking and family naming seem to be major causes of font defects on Windows. Even when fonts are functioning as intended some users may be confused/annoyed by style-linking. For example in Word, there is no easy way to tell if you’re using a real face or simply styling the text.

The easy solution, of course is to make sure you’re testing with applications customers use. Also, it is good to have an open chanel of communication back from customers. Many users will blame the application first. It may take several users before someone realizes that the font itself is defective.