Plugin for Opera. DOM-tree modification

I want to create a plugin for opera that modifies tha DOM-tree after the page have been loaded. Does opera 开发者_Go百科have an appropriate plugin API?

---

Opera now has an extension API. Here's a link to a documentation entry point: http://dev.opera.com/articles/view/opera-extensions-hello-world

---

Opera supports the NPAPI plugin API (whic powers flash, java, etc), but I suspect you are referring to an extension API like Firefox, Chrome, and Safari have. Opera does not have a comparable extension API.

Edit by Hallvord: this answer is outdated. While correct at the time, Opera has now developed extensions support.