Others, like Galapagos tortoises, may need the relative isolation of an intermittent Net connection. To allow the creatures to seek out congenial homes, Ray has given them access to a modified version of the Internet Ping command. Ping is normally used to discover whether an address is valid, and whether a computer with that address is connected to the Net. The modified command, Tping, allows Tierra's digital creatures to ask questions about the environment on a particular computer. A faster processor means there are likely to be more spare processing cycles that the creature can use.
More memory means more resources.
If there are only a few, there will be less competition. Finding a niche Ray and his colleagues do not know how the creatures will use this information, but it may be that they evolve a capacity to relate information gleaned with Tping to their ability to survive. The high-powered band of volunteers that makes up the Tierra Working Group draws its members from the Santa Fe Institute in New Mexico, supercomputing centres in the US and private companies. They have adapted Tierra to run on a variety of operating systems, from Unix to Windows 95 and Macintosh. The creatures have no access to Internet addresses.