Can this be considered a replacement for multisite?

The module is designed to replace multiple installations. It also makes different assumptions than modules such as OG Multisite.

You should consider how you want to share and manage content before using this module.

Read the use case in the README:

1.1 Use-Case

The module was initially developed for a web site that sold franchises of a
monthly magazine. The publishing rules were as follows:

- Content may belong to the national site, one or more affiliates, or to
all affiliates.
- National editors may select to promote affiliate content to other
affiliates, the national site, or to all affiliates.
- Local editors may only create and edit content for their own affiliate
sites.

These rules are enforced programmatically by the Domain Access module. There
was concern that, if given a choice to make, local editors would not assign the
content correctly. Therefore, the module handles this automatically, and local
editors have no control over which subdomains their content is published to.

Also pay attention to section 3 of the README documentation.

I would expect the first stable release by the end of November.

That would go more quickly if we had more beta testers. If you have a test site -- not your production site -- please install the module and report any issues you run across.

See http://groups.drupal.org/node/6444 for a long discussion of OG.

Simply put, I have not tested the module in conjunction with OG; Drupal can have trouble when two node access modules run on the same site.

I have written the Domain Access module to be extensible, so, in theory a Domain OG module could be written to address any issues that arise when using both modules together.

It may be that the Domain Prefix module -- which I should release in beta6 this weekend -- will eliminate the issue by allowing you to use OG tables on specific domains.

That said, I do not have the resources to test OG extensively, so I'll be counting on people to test how the modules interact.

I would wait for a stable release. Two basic reasons:

1) I cannot provide individual support for questions pertaining to how the module will function for individual sites:

my site uses organic groups, buddylist, privatemsg, mass contact, simplenews, classified ads, forums, among other modules.

2) http://drupal.org/node/191375 and possible fundamental changes to the module.

That said, it is "use at your own risk" and I plan to provide an upgrade path from beta6 to the final version. So if you want to use it and 'proceed with caution' go right ahead.

Just understand that there still may be unknown bugs. What I really need are testers who can uncover those and not panic.

The core changes are ongoing in the HEAD branch of the module. They are internal changes, though, and should not affect the current functionality.

The stable version really can't be released until OG integration is properly addressed, since many people -- including the project sponsor -- want that integration.

What I think I'm going to do about OG is the following:

- Write a patch to the node_access() function to enforce the behavior that I need.

- Document and submit an API change for Drupal 7 that uses the patch.

The proposed patch will not change the current behavior of node_access(), but it will _allow_ that behavior to be changed by modules such as Domain Access.

The patch would be distributed with the Domain Access module and would need to be applied to sites that use multiple access control modules (like DA and OG).

More detail (technical detail) over at: http://drupal.org/node/191375

Yes. There is progress to report.

See http://drupal.org/node/191375#comment-635244

I'm in the process of preparing a core patch for Drupal -- likely to be filed as a feature for D7 due to the release schedule. However, the patch for D5 is in early testing and can easily be prepared for D6.

Next step is to commit some of the changes to Domain Access that make use of the ability to run multiple access control schemes in parallel.

I would expect a beta7 release by Sunday of this week, assuming that I actually do some work during this American holiday weekend.

I'm about to commit these changes to HEAD. They are definitely for testing only.

It just so happens that we're going to be testing this stuff at work in the next two weeks, so that should lead us to a stable release.

I have committed this to HEAD. Closing this issue.

Keep an eye on release notes. I need to do some more testing before beta7.

OG integration is in beta7, but requires a core patch.