Janrain Engage allows your visitors to login to your site with their existing accounts on Facebook, Google, Twitter, Yahoo!, LinkedIn, Windows Live, MySpace, AOL or other networks and then share their comments, purchases, reviews or other activities from your site with friends on multiple social networks.
I hate being dependand on third parties, especially when it's a third party handling third party api. I rather just have separate facebook and separate twitter and separate google/openid. But after facebook i think the easiest alternative is twitter to create accounts. would love to see it.
I've personally found these 'social login' options to be fairly pointless on any platform/system. You still end up having to create an account, it just fills out 2-3 fields for you. True integration would be logging in, hitting the 'allow' button on the given login service, and be done. But nobody seems to have figured out how to do that yet without forcing you to fill out a bunch of fields when you return to the site.
The need for this isn't all that great if you have just a few thousand members honestly. But when you have a very large community and you're trying to engage more users/prospective users, logging in via OpenID/OAuth is a great way to convert new site visitors. The reason is they don't have to remember yet another login. We need this at MODX, and it would very much make a positive difference based on the discussions we've had with our users. We want to lower as many barriers to joining our community as possible and get people participating.
I try not to use Facebook as a login source (I simply don't have a high degree of trust with FB) but I would a Google ID or a Twitter ID, or My OpenID. FWIW, JanRain helped create the OpenID specs and delivered the first implementations of it, so I'm fairly certain they're not prone to wantonly (or naively) break things. Their entire business depends at the core on logins working perfectly every time.
<MAJOR-OFFTOPIC> Are there any plans to build an integration for XF -> modx? I have been a modx user for a long time and would love full user/permission sharing</MAJOR-OFFTOPIC>
<ON-TOPIC> I would love to see more login methods, even for smaller sites making it easier for users to participate will help with that initial conversion of Guests -> Users.. And things like twitter will give you another way to contact that user also.
Hoping for this in the some what near future</ON-TOPIC>
We're evaluating switching from SMF at MODX, but we need to dive into XenForo's authentication code. We have not bought a license yet so we can see the code, but my gut says it would work. By the same token if it doesn't, we don't want to flush money down the drain if the initial code review proves that it's not an appropriate solution for us. If we adopt XF and create a bridge we'll absolutely share it.
At MODX we have a lot of infrastructure supporting the project and our business: issues in Redmine, forums, documentation in Confluence, bugtracking at GitHub, a donations/support infrastructure with checkout PCI compliance handled via FoxyCart, and SSO handled via Atlassian Crowd. Then there's some private applications we developed to manage the pending Partner Program and Commercial Support launch.
We can't have isolate islands of users that are unlinked across all our operations/services, and admittedly solving this particular problem is not as easy as it sounds on the surface. We've had success with Crowd to date as a federated authentication platform. Currently our forums are the last piece that needs to be brought into the fold. SMF should support OpenID logins when it finally hits 2.0, and it should then therefore work with Crowd I think, but I'm uncomfortable with several of the things related to SMF in general.