从其他内容管理系统迁移到SharePoint

I am currently working on a project which requires migration of content from different content management Systems to SharePoint. Are there any good, preferably open source, tools that would help me do this? Also, what are the best practices that I would have to keep in mind when it comes to such projects. One more thing that i would like to factor here is reusablity, because we might have to work on similar migration projects, from other Content Management systems in future. I am currently working on a project which requi