Silverspring Soundfont
Silverspring was a GM/GS bank in Soundfont 2.1 format. It was entirely composed of public domain samples (or free-for-use instruments). Originally, there was a bank needed for playing back the classic games' (Descent, Heretic/Hexen, Doom series) MIDI soundtracks. Silverspring was compiled for that.
It was meant as a near-64 MB (depending on version and completeness, the bank size varied from 56 to 80+ megabytes) bank for SB Live cards under NT4. A friend also used the bank (and larger derivatives) under the MacOS X Quicktime synthesiser.
Under NT4 and NT5 native Creative drivers, there was trouble with MIDI playback: the SB Live cards are limited to a 32 MB memory allocation (they can only play back 32 MBs of samples at a time). The "professional" version of SB Live, the EMU APS Live, was specifically limited to 32 MBs max. RAM cache. The SB Live, though, had "unlimited" memory cache limited by RAM size. The Creative Labs drivers never implemented the caching model correctly (keep only 32 Mbs accessible by the card, dynamically managing the rest as PC-only Soundfont cache), always having some kind of trouble with MIDI playback - under NT4 it was instruments/layers dropping out of playback, and the card eventually filling with garbage its own playback channels (after about an hour of playback, the wave channels became inaccessible), under NT5 the engine seemed to be improved a bit, but layers of instruments weren't played back if there were too many of them, pitch often wasn't kept up with (especially noticeable with orchestral string instruments), and the overall sounding was more artificial and plastic compared with NT4. All-in-all, Liveware 3 for NT4 was maybe the last decent-sounding release, in spite of memory management problems (it could play a piece with all the instrument layers in place and as intended, even if the card would bang out after playing back several complex pieces).
There was the kX driver project, but its Soundfont engine didn't support stereo playback, it didn't support Soundfont 2.3 features, it had trouble playing back more than one layer per instrument, trouble switching to non-standard sample frequencies, etc. etc.
It's been a certain surprise the bank is still requested and used by some people (it should sound more or less decent on the Audigy cards, which have no 32-MB limitation and related trouble).
A few days ago, a message came from a Korean Soundfont folk with a New Zealand address, asking for the extras that came with Silverspring 1.5 and any current download links. Well, "current download links" there are none (there used to be a German mirror that eventually went down because of multi-gigabyte traffic), but he did provide a link to a Soundfont review site where Silverspring was commented on.
There the downloaders wrote the bank had poor basses and drums, but the best MIDI guitars in a Soundfont.
Different releases of Silverspring had different guitars (and there was a larger, "more hi-fi" version of Silverspring with different drumkits and attenuation tunings called "Savria" that was made specifically for playing Kevin Schilder's MIDI soundtracks to Raven Software fantasy games): the first version of distorted electrical was called "Quite-distorted Guitar", a multi-layered monster that had a raspy sounding (this piece from Descent shows it off), the second was a triple-layer (left, right, and centre-panned, delayed mono-sample layers) distorted guitar inspired in Justin Broadrick's delayed and reverberated guitar sounding of his Godflesh rock project. The overdriven guitar through most versions was a "Well-overdriven Guitar" instrument, also multi-layered with some barely-noticeable distorted electric muted guitar chords thrown in for a more "metallic" sounding. It was dropped for release 1.5, replaced with a Casio Overdriven guitar that had some trademark reverberation/chorus/layering effects on it. Here is a sample of the Well-overdriven, Bobby Prince' soundtrack to Doom level 1-8, "Sign of Evil".
Basses and percussion... Some of the basses in the public version of Silverspring were replacing the commercial bass instruments that were used for mixing and rendering some pieces; the picked bass instruments different Silverspring versions had, were usually replacing a Sonic Implants sub-bass. The fingered bass in different versions was good though (with its characteristic "Velvet-Undergroundish" sounding), as were the two synthesised basses (the first was a Moog, the second a very-lowpass resonating saw wave bass). The percussion kit was a modified Sound Canvas kit with more stuff thrown in to make it sound more natural (and almost always was replaced by a Natural Studio Kit 5 in actual mixes and renderings, also in the Savria version). Silverspring was used as a "base" bank to build upon, and stack instruments on top of it.
A version was made for the NT5 SB Live drivers, dropping some instruments' complexity, losing layers and so on, with a new drumkit and less complex guitar instruments.
It never quite got through, although it did have good sounding on some pieces (by that time, that was enough), mostly with the Doom/Descent MIDI tracks.
A recording quite never captures the sounding of a good "live" synthesiser (there's always some quantising and dithering involved in 16-bit wave recording that the less discrete "live" playback with instruments mixed with 32-bit interpolation and audio depth doesn't have), but here are some samples...
Descent Level 4 track, one of the earliest versions of Silverspring, all instruments are from the bank. Track-by-track mixing in a wave editor.
Oxygene 10 (Lost Soul), a mix by Howard Farrar for the AWE64 card; usually, Silverspring handled MIDI pieces sequenced for "classic" hardware well; the version is 1.5.5 (NT5), the last one. Additional instruments are an experimental synthesised strings patch that didn't make it into the bank (made with Wavecraft, an analogue emulation non-realtime synthesiser), Yamaha OPL3 FM Bass 1, and Elka Synthex Jarre harp. Recorded under NT5 with SB Live and a custom EAX preset.
Borkesis - a piece from Hexen soundtrack, "live" recording under NT5. All instruments are standard.
...the soundtrack to "Lava Pits", a Heretic level. The only bank instruments here are the synthesised strings, the base fretless bass patch, and the melodic tom.
And a very beautiful piece, reverbed twice, from the Heretic soundtrack, the finale of episode 2.
There was a Canadian musician, Christopher Payne, who composed some albums with instruments from Silverspring and related banks. Also, there was a musician friend who used the instruments from the bank for his own works; he used to have a university band called "Kernel".
There should be other musicians who have played with the bank (although, it was mostly intended for listening to classic games' MIDI tracks with cheap hardware).
An acquainted composer once said the pieces sounded good (mixing-wise), but "compressed". They really might; after all, a lot of lowpassing and other trickery was used for the instruments, with a lot of EQ shaping done during mixing in the track editor. Though, for a Soundfont bank, Silverspring still had some of the more realistic sounding at its time.
Work on an already worked-over project is always akin to flogging a dying horse, so Silverspring most likely won't ever have a "really final" version.