interesting node modules

There are so many node modules out there to the point that sometimes you can have several different ones that appear to solve the same problem.

node.js on GitHub has a list of classified node modules, but still it is quite difficult to pick the best one (in terms of node version compatibility, easy to use, still actively developed, good performance, etc.).

It would be really cool to have some sites that actually give reviews and code samples of using these node modules. If performance comparison can be provided, that is even better.

Inspired by "6 Must Have Node.js Modules", I am listing the modules that I found quite interesting and useful to the current work:

HTTP clients: 

• node-wwwdude
• request

XML to object conversion: 

• node-xml2js, a fairly lightweight and fast xml to object conversion library
• node-expat, a very high performance SAX lib, native binding to libexpat, it has a fork with object conversion support

Image processing: 

• node-canvas: canvas implementation based on Cairo
• node-qrcode: QR code generator