Does anyone know of a good open source comments module?

Question

I want to add the ability to submit, moderate and display comments on an existing set of websites. Surely there's already a bunch of open source components that can handle the following:

1. Comment submission
2. Markup validation
3. Private comment moderation
4. Threaded comment display
5. Locally installed (so works seamlessly with my existing registered users)

I've looked at a couple of systems e.g. disqus and they fall down because they're either hosted remotely, or don't hook in to my existing registered set of users.

Our existing systems are implemented in Java, so it would be an added bonus if the commenting system was Java, too.

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An interesting aside is that Google turns out to be next to useless for finding commenting modules, due to the sheer volume of pages on the net that contain the word "comment".

Answer 1

Well, I think the problem here is that to comment, one really needs to comment on Something, so pretty much any app your find will also include the Something (like a blog engine).

Further, without knowing what that Something is on your website, it's kind-a hard to write an app that will attach comments to it.

Answer 2

Check out Demi Sauce.

From the Google Code description:

Demi Sauce is an application that offers web services to other applications. It operates as a server in your environment that other applications use like a software component using either Javascript embeds, or xml web services. Rather than building on top of a framework to get additional capability above your native app, Demi Sauce is all web service based to keep it separated but easily integrated with your software application. You would use it within your existing application by calling simple web services or embedding javascript into your app (like google analytics, but for comments, feedback/help etc. This allows the same content and services provided by DemiSauce server to be consumed within multiple applications within your environment.

Answer 3

As for spam on your forum, you could use Mollom (http://mollom.com/).