It turns out that, indeed, many MMORPGs (Massively Multiplayer Online Role Playing Games) are running Linux on their back ends. Christian Berentsen, the operations director of Funcom (www.funcom.com) kindly agreed to a virtual talk with Dee-Ann LeBlanc, LinuxWorld Magazine's gaming industry editor, about how Anarchy Online (www.anarchyonline.com) uses Linux to bring the world of Rubi-Ka to life for their user base.

LWM: Please tell us briefly about Anarchy Online. I know it's a science fiction MMORPG since I used to play it, but tell us a bit about the game world and the game.
Christian Berentsen: Anarchy Online takes place on the planet Rubi-Ka, almost 30,000 years from now. Rubi Ka is important to the corporation Omni-Tek due to the presence of a rich notum ore. Notum is a mineral that enables "hard" nano-technology (a step forward from the soft, biologically based nano-technology). The planet has been terraformed to some degree, and several cities and natural expanses have been developed by Omni-Tek. Omni-Tek treats its employees in a manner that leaves a lot to be desired.

After a few generations, the revolt emerges. The player takes part in this world by choosing a breed, gender, looks, and a profession, then evolves the character from there. The player can choose sides in the conflict or stay neutral. The game world is large and beautiful 3D scenery, where the players can explore, team up, party, do missions, fight, form large organizations, and do many other things left up to their imaginations. Central to the game is the character development that's based on gaining experience from fighting, doing missions, assembling items, and other things. The characters can gain levels up to 220, and in that process they have a lot of fun. Every character will have a different experience and become a unique citizen of Rubi-Ka.

LWM: Where is Linux involved in AO's back end?
Berentsen: All our servers run Linux. Our game servers, database servers, login servers...the chat server is running FreeBSD.

LWM: Why was Linux selected to handle the back-end tasks that it handles?
Berentsen: We started by having a few different Unixes in our development phase, and gained some experience with the different products (Irix, AIX, Digital Unix, some Solaris). In this heterogeneous development environment it was more of an evolutionary process that made Linux survive. The other OSes had some strengths and weaknesses (for example tools, good or bad debuggers). In the end we realized that the platform we had most control on was Linux, and we believed it to be suitable for deployment on our live sites.

LWM: Why were the other back-end platforms selected to handle what they handle?
Berentsen: We have one FreeBSD machine running the chat server. Back then it was the only OS that could realistically handle the number of connections we required.

LWM: What type of setup is this back end? Clustered? COWed?
Berentsen: We have several "dimensions" that are disconnected from each other. Each has its own database server and set of game servers that run parts of the world (playfields) on them. We have automatic load balancing of playfields onto servers, and some static load balancing.

LWM: I know that this was a long time ago for you, but what were some of the challenges involved in building your MMORPG? Were any of them Linux specific?
Berentsen: The main technical challenge was to be able to support a large number of players and objects in a large world. Profiling was a challenge on all the operating systems, and we developed our own profile viewer (for gprof) and later also a LiveProfiler (not using gprof) for server performance profiling on the fly.

LWM: What technical lessons have you learned along the way?
Berentsen: There are many things we have learned from making AO, on many levels. Choosing open source middleware has proven very valuable, and has supported our portable development strategy well. Think about scalability early on, even in the game design.... Make tools for operating the game early as well. We think we have done many things right, and been able to select out the bad directions early.

LWM: What business lessons have you learned along the way?
Berentsen: Do not launch prematurely. Have a longer beta and fix all showstopper bugs before launch. We have released many content and bugfix patches since release, and the game is very stable now; the first week was kind of rocky in that area.

LWM: Is there a Linux client? I know there wasn't when I changed from a Windows to a Linux desktop, that's one of the reasons I ended up having to leave the game, but things do change.
Berentsen: There is no Linux client; we started porting the client renderer to OpenGL at one point, as the start of the porting process, but it was abandoned.

LWM: Do you plan to provide one?
Berentsen: There are no current plans to provide a Linux client.

LWM: What would have to change in order for you to consider such a move?
Berentsen: We might consider this if Linux becomes a desktop OS of choice for gamers. We know there are games being ported to Linux, and that a lot of the Linux community plays games, but currently we do not think the market for AO is big enough in this segment.

LWM: Do you plan to stick with Linux in your infrastructure at this same level when you begin your next game project?
Berentsen: We will probably stick to Linux on the server side. Our server code is platform independent, and we embrace open source. We will probably use Linux at the same level as now, with a hybrid development of server on Linux and client on Windows. Probably a lot of the tools we will be using in the future will be platform independent, so if people in house have Linux desktops, we will support that for our developers and content providers.