Multiple File Upload Options

I was recently confronted with a question about how to do multiple file uploads from a browser based application. The HTML 4.x specification is pretty open on the file upload requirements, and all of the browser implementations are very basic.  Firefox, Safari, Web Toolkit, and Internet Explorer all provide a method to upload one file at a time, but no multiple file upload. As a result, clever coders have come up with a number of solutions. Here are a few.

• Ajax Upload; A file upload script with progress-bar, drag-and-drop - This is my pick.  Disclaimer: I contributed the servlet code to handle the requests. Here is a link to the source: File Uploader (GitHub).
• AJAX Multiple File Upload Form Using jQuery - Based on Andrew Valums original work.
• Google App Engine and File Upload - Google App Engine method.
• Safari 4 Multiple Upload With Progress Bar - Limited by by browser type.
• Upload multiple files with a single file element - a different approach. Very simple to implement.
  jQuery Multiple File Upload Plugin - This worked but was very flaky for me. The first item works better.
• FancyUpload - Swiff meets Ajax (v3.0) - I did not experiment with this one. I as told about it, but I had already decided on working with Andrew Valums on his elegant solution.

These are some approaches available to you. If you are using a JSF based framework, a number of them already include a multiple file upload component based on Apache Commons File Upload.