A significant percentage of the prolific technical contributors are members of both organizations. Therefore, there is a significant amount of cross-fertilization between the organizations and an attempt to use each others existing specifications and not do the same work twice, especially if it's conflicting work. Further, OASIS has as a stated goal that it has a collaborative relationship with other standards bodies. This can be seen, for example in the WS-Security specification, which uses a number of specifications from the W3C.
Another important factor is the participation of user organizations, not just vendor organizations. Both W3C and OASIS are open entities, which means that is important for eventual users of the technologies to join, vote and make their desires known to the various technical committees. So a good part of the successful collaboration will depend on you, the user organizations, to foster cooperation and synergy. This is the time when user organizations need to step up to the plate.
The above does not mean that there is not competition or disagreement between the organizations on certain issues, there is. Also, there are times when vendor companies have an agenda that they would like to see in specifications. However, since the process is an open process, in the majority of situations a good technical argument will win out.
On balance, give the above, I believe that the W3C and OASIS as well as other standards organizations will compete but will carve out their particular niches and will continue to use each others work as building blocks. Yes, they will have territorial squabbles, but I believe both organizations realize, especially if they are prodded by the user organizations, that unless they produce meaningful and useful specifications they will not survive in a meaningful way. A second strong determinant for this position is the many technical members who are members of both organizations and who contribute the technical lifeblood to both organizations. Bottom line, I believe that both organizations will produce solid specifications and that, hopefully, the competition will be positive and synergistic and will not produce dueling specifications.
This was first published in June 2003