Fifteen years back I struggled with the problem how to emulate the sound of old instruments with banks available in various synthesizers. I had to abandon the project yet during the following years from curiosity I've checked web from time to time if some soft synth producers would come with medieval and renaissance library. Everyone was trying to cover world music, but the European music of Middle Ages seemed to be of no interest.
When I stumbled upon ERA II Medieval Legends I first didn't believe it is the library I'm looking for.
Visually it looked like many similar thematic synths which are trying to sell "mood" or "atmosphere" without using sound of authentic instruments. But when I watched one hour long detailed walk-around video on Youtube, all instruments demonstrated one by one, I was caught. Although I play completely different music nowadays I've bought it immediately.
It's really joy even to test-play various instruments and I hope I'll be able to get some of these sounds into my music in the future.