I'm extremely excited, so please forgive me. Also, you might already know this for a while. But I think it is more than worth to share this.
As a composer/producer you probably know how expensive professional orchestra libraries can be. Paying thousands of dollars is not unusual.
But there's a professional alternative that comes for free! The Grammy award winning Philharmonia Orchestra, based in London, has created an awesome sound library over the years, that they offer under Creative Commons Attribution-ShareAlike 3.0, allowing the use in commercial products. The only restriction is that those samples may not be offered as a sampler instrument.
The library is so comprehensive, so detailed, that it is hard to describe everything.
Let's just look a the violin. Recorded in half tone steps from A3 to G#7. Every half tone recorded several times in different lengths, dynamics and articulations. In total there are 27 articulations (Arco, glissando, vibrato, etc.), 8 dynamics (Piano, forte, crescendo, etc.) and 7 lengths (from 0.25s up to 2s, including phrases)
And the library not only offers the usual orchestra instruments like violin, cello, trumpet, oboe, clarinet, etc. It offers a total of 19 instruments, among them rather unusual instruments for a classic orchestra, like guitar, banjo or saxophone.
Additionally, it also offers 39 percussion instruments, again with different articulations, dynamics and lengths, where it makes sense (e.g. Bass drum), including exotic one likes a train whistle, washboard, thai gong or djundjun.
For those who are afraid of building their own instrument from it, there are Kontakt 5 templates. Since a ready made sample instument isn't allowed to be offered, that's no functioning instrument and it comes without samples. Instead:
"In order to comply with the wishes of the folks who have given us these fine samples, I created only shells distributing neither samples nor a functioning instrument. You can download a shell and then drop wave files with the appropriate names into the samples folder." Those shells do not include all instruments and no percussions.
I only own the Kontakt 5 player, so I'm not sure if I can use this. But I will convert the Philharmonia library to other tools I use. And I'm sure, you will want to also
Here you'll find the Kontakt shells: http://bigcatinstruments.blogspot.ca/2014/04/diy-philharmonic-project.html
And here you'll find all the samples from the Philharmonia library: http://www.philharmonia.co.uk/explore/make_music