So far, a few steps have been taken toward this goal. Jon Watte, CTO of Forterra Systems, has proposed a possible standard designed at his company, called paged terrain format, which he hopes can keep virtual worlds literally on common ground. The format, if adopted, would allow developers to create landscapes so that multiple systems agree on the features of any given terrain. Paged terrain format is particularly designed to allow developers to use high-quality graphics, a feature that Watte says is missing from existing terrain standards, which were developed by the military. Forterra plans to make the specification for the format freely available.

Other companies, including Multiverse and Linden Lab, have designed platforms that independent developers can use to create virtual worlds more easily than building them from scratch, resulting in networks of virtual worlds that are interoperable, since they share the same foundational code. Although these networks of virtual worlds are a small-scale version of what a 3-D Internet might eventually look like, further standards need to be developed to interconnect worlds built on different platforms.

Corey Bridges, cofounder and executive producer of Multiverse, says that his company has created code that developers can insert at their discretion, which would allow users to bring their avatars across world lines using the Multiverse platform. Bridges says that a key problem is making a platform flexible enough that it doesn't force developers to create the same world over and over again, while maintaining the consistency needed to keep the worlds connected.

Cory Ondrejka, CTO of Linden Lab, says that the first step toward bringing disparate virtual worlds together is to search for existing candidates for standards. He plans to look at systems such as OpenID, which people could use to store information about their identities and transfer it between worlds at their discretion.

Lanier, who notes that he has many professional connections to people involved with virtual worlds, says that while he very much wants the 3-D Internet to succeed, he is skeptical about whether it will be possible for developers to agree on a set of standards. "There's a virtual land rush of people who want to come in and grab the standard," he says, noting that the history of IBM and Microsoft provides some indication of the money that can be made by establishing a standard. But Lanier thinks a successful standard for the 3-D Internet is unlikely to develop the same way that HTML did--that is, as an abstract definition that people then adopted. He thinks it is more likely that a well-designed package will become a standard, similar to the way that Adobe Flash is becoming standard for rich Internet applications.