I'm looking into the possibility of integrate Bitcoin functionality into an existing GPL software product, the problem is that it seems to be hard. The one true implementation brings with it some additional dependencies such as wxWindows (which is actually pointless if you're just interested in the functionality and not the GUI), BerkeleyDB (which is a bit much for storing just a bunch of keypairs), openSSL (which is reasonable as it's use is very wide-spread, but i'm not entirely sure why it is required as the set of crypto functions in Bitcoin is fairly limited afaik) and Boost (which is huge to introduce in an existing project when it's only needed for Bitcoin functionality). Especially on Windows is including those libraries far from a straightforward task and building a 64-bit binary for Windows is just a pain.
I don't really have a problem with the fact that a one true implementation is preferred, because I understand more implementations will introduce complications in this early stage, the examples where this method is successful are few (Perl is maybe one of the very few exceptions probably because it's very well-documented). I think in the long run multiple implementations are going to be required if Bitcoin is to grow (a lot) larger. Keep in mind that in time perhaps other devices with much more esoteric platforms may want to be able to have Bitcoin functionality as well (smartphones were already mentioned, but think about automated payment servers, set-top boxes, vending machines, pay-toilets, ...). Bittorrent, which is mentioned here as an example, is currently running on the firmware of some people's networked harddrives. Maybe on-chip implementations of Bitcoin will be made one day.
Being able to run Bitcoin in javascript (with an AJAX proxy) would be a significant advantage for the application I'm thinking about.
I think what would be needed is a very low-dependency reference implementation, which can easily be translated into other programming languages without introducing new bugs or incompatibilities. In time the protocol should be standardized and perhaps even go for recognition by standards bodies. That's the best way to guarantee long-term survival of the network. Every platform in the world that could be capable of using Bitcoin has at least a decent C compiler and the current de facto standard way to have a low-dependency reference implementation is to have C library which can be easily compiled on all major platforms without (or with absolute minimal) dependencies. The stock client should also use that C library.
Emphasis mine.
I registered just to reply to this and offer some insight. As a unix-type, I insist that modularity is important. By reimplementing specific cryptographic transforms rather than using something like openssl, the programmer risks all sorts of problems (recall the debian openssl fiasco a while back). The work has already been done by competent experts and is well-tested. Rolling in specific algos in lieu of calling openssl encourages "getting cute" with important components which are
best left alone, especially when dealing with financial crypto.
The best approach is to standardize protocols (RFCs) and provide an open (BSD/GPL) modular "reference" implementation. An excellent example of a successful execution is GnuPG.
P.S. Someone, in either this thread or another, raised the point that communicating via IRC seems to be a rather obvious point of failure. I may be totally misinformed, but if this is true, it goes to my point about the importance of protocols over implementation details. A de facto reference implementation already exists; perhaps it is time to aggressively tackle some other problems via protocols. I am confident that an ecosystem of implementations will emerge naturally, similar to bittorrent.