How to run Twister on ARM (Debian) and OSX

I'm growing very fond of Twister, a new project from Brazilian developer Miguel Freitas. Miguel basically leveraged Bitcoin and Bittorrent concepts (and code!) to build a fully-decentralised Twitter clone. The P2P architecture means that it's completely immune to censorship and "chilling effects": nobody in the network can hand your account over to the authorities or disclose who you are, nobody can delete your posts -- and neither can you, so be careful what you post :)

It's definitely early days (it's still a bit hacky to set up, and the html interface needs work), but I've decided to help a bit, so I managed to make it work on OSX and now on my little ARM-based always-on home server, the CuBox. Like most lightweight P2P services, Twister is perfect for long-running, low-power ARM instances (Raspberry Pi etc), so this is what you'll need to know if you want to set it up there.

1. Download all libdb4.8* packages from Bittylicious. Berkeley DB 4.8 is a Bitcoin requirement, and at this point in time there's no way around it. Unfortunately, recent distributions (i.e. Debian Wheezy and newer) replaced it with 5.1, so apt-get won't help you (NOTE: if you don't care about wallet compatibility with already-running instances, you can just use libdb5.1). You can compile libdb4.8 from source if you want, but they'll require about 500 MB of dependencies (java, X etc); the Bittylicious packages worked fine for my vanilla Debian install. There's a chance that BDB as a whole will be dropped at some point in the future.
2. Download other dependencies: openssl-dev, libboost-all-dev, miniupnpc (miniUPNPc is technically optional but strongly recommended, it makes it a breeze to go through firewalls). These should come down fine with apt-get. Note that OpenSSL should be version 1.0+ (check by running openssl version). NOTE: it's been reported that default Fedora openssl packages (built without support for Elliptic Curve crypto) will make Twister crash at the moment. Make sure you find alternatives until the bug is fixed.
3. clone Twister repositories:
   git clone https://github.com/miguelfreitas/twister-core.git
   git clone https://github.com/miguelfreitas/twister-html.git
4. prepare your configuration (note: DON'T edit user and pwd, they're hardcoded elsewhere at the moment):
   mkdir ~/.twister
   echo -e "rpcuser=user\nrpcpassword=pwd" > ~/.twister/twister.conf
   ln -s /path/to/your/twister-html ~/.twister/html
5. Follow these instructions to build twisterd. You might want to link it under /usr/local/bin once done.
6. Launch it. Give it 5 to 10 minutes to download the full blockchain, then connect to http://your-server:28332/home.html . You'll be prompted to create an ID - do so.
7. After creation, make sure you backup your key by doing:
   ./twisterd dumpprivkey my-user > my-key.txt
   Backup my-key.txt (or just its content) in a safe place, it's your all-important key: you lose that, you lose access to your ID and there is no way to get it back!
8. You should also backup ~/.twister/user_data as it contains your direct messages; these can theoretically be retrieved if lost, but it takes a while, so it's probably good practice to just back them up regularly.
9. Enjoy! The community is very small at the moment, so feel free to go on a follow-spree. There are two mailing lists, Twister-Users (more active) and Twister-Dev (more technical). The project is brand new (Miguel released it at the end of November 2013) so expect a bumpy ride, but the community is very friendly and in need of help with HTML and jQuery as well as C++, if you can spare some cycles :)

For OSX, the process is slightly more convoluted at the moment, so I documented it in the official doc/build-osx.md. Note that I'm not a make guru, I'm certain that there's plenty of room for improvement there -- feel free to contribute!