Network Tierra FAQ

Go to Tom Ray's home page. Go to the Tierra home page.

The proposed project will create a very large, complex and inter-connected region of cyberspace that will be inoculated with digital organisms which will be allowed to evolve freely through natural selection. The objective is to set off a digital analog to the Cambrian explosion of diversity, in which multi-cellular digital organisms (parallel MIMD processes) will spontaneously increase in diversity and complexity. If successful, this evolutionary process will allow us to find the natural form of parallel and distributed processes, and will generate extremely complex digital information processes that fully utilize the capacities inherent in our parallel and networked hardware. The project will be funded through the donation of spare CPU cycles from thousands of machines connected to the net, by running the reserve as a low priority background process on participating nodes.

The concept for the network initiative is described in the following manuscript:

Ray, T. S. A proposal to create a network-wide biodiversity reserve for digital organisms. ATR Technical Report TR-H-133.

Let me make some comments in response to frequently asked questions that are not answered in the manuscript:

The World Wide Web is a sub-net of the internet. It is created collectively, as the result of many people running web servers on their machines. This collection of web servers creates an open space, within which, anyone with a web browser can move freely, accessing the data on the disks of the servers that is made available through the web server software. Note that web browers can not access other file systems on the servers.

The Tierra network will be another web. It will be created collectively as the result of many people running Tierra servers on their machines. The Tierra server is a piece of software written in the C language, which creates a virtual machine called Tierra. Tierra does not self-replicate, evolve, or experience mutations. Tierra does not migrate on the net. In order to run a Tierra server, you must download the software from its ftp site and install it.

The collection of Tierra servers creates a sub-net of the internet, within which digital organisms and Tierra browsers (Beagle) are able to move freely, accessing the block of RAM memory that is made available by the server. Note that the digital organisms and Beagle can not access other RAM on the machine, nor may they access the disk.

Digital organisms can not access machines that are not running Tierra servers. Tierra uses protected network (IP) addresses, analagous to protected memory. On multi-process operating systems, programs do not directly access memory. They must make requests through the operating system, which provides them an indirect handle to the memory segment allocated to the program. Analogously, when a digital organisms suggests a network address where it would like to migrate or TPing, the Tierran operating system converts the requested address to the closest matching address of a participating Tierra server. Digital organisms do not have direct access to network addresses. All such access must pass through the ``protected network address'' mechanisms of the Tierran operating system.

More discussion on network Tierra security issues can be found in the report of the First Tierra Workshop.

The network system is operational, but is still considered to be in the development and testing stage, so is not ready for distribution yet. At present it is fully functional on both unix, Amiga and VMS platforms. Development for Mac and Windows platforms should take place during the next six months. The Tierra system will be run as a low priority background process (like a screen saver) at all times, and so will only soak up CPU cycles not being otherwise used by the users of the node. Thus the network Tierra should have a minimal impact on the performance of the nodes where it is installed.

Although we ask for a long term commitment by those who choose to participate, this does not mean that the Tierra process must run continuously for long periods. The Tierra process on any particular node may be brought up and down whenever it is suitable to the users of the node (the Tierran creatures will experience down-time as a local catastrophe). Participating nodes must be connected to the net, but presumably any kind of connection will be suitable, including intermittent, such as by modem. We will have to deal with special cases as they arise.

I have received a lot of interest from people who have Macs or PCs at home, who connect to the net via modem. This is fine, and adds interesting temporal-topological properties to the environment of the digital biodiversity reserve. However, the system was initially developed for unix with continuous network connections. However, we already have a fully functional Amiga version working over a modem, and the Mac and Windows versions will follow.