PadCaster is a command line tool that converts MacPAD application description files to RSS 2.0 feeds. A MacPAD file describes one application; it contains the same information as is found in a versiontracker posting. Thus, the feed PadCaster produces provides RSS software update notifications. Fraser Speirs coined the term Appcast for such feed.

For developers:

PadCaster is an easy way to provide an Appcast feed for your app while patching into existing MacPAD goodness.

  • Tools in the MacPAD SDK make it easy to author MacPAD files and include auto-update within your app.
  • Structured, easy to parse MacPAD files open the door for other applications. Shovel by M. Uli Kusterer is a MacPAD-powered software update clone for third party software.
  • A MacPAD file will automatically feed, and hopefully more aggregation sites in the future.

For users:

If your RSS aggregator supports scripts-as-feeds, then PadCaster lets you get an update feed for any app that has an associated MacPAD file. This would be a lot cooler if more applications supported MacPAD. Still, many applications listed at do already support MacPAD, and you can discover URLs for MacPAD files by clicking "Modify Listing" on postings. The excellent NetNewsWire 2 supports scripts-as-feeds.

Other resources


  • Mac OS X 10.3
  • familiarity with the command line interface


From the command line,

PadCaster [--verbose] <MacPadURL>
Test it out with
--verbose spits out warnings that a developer producing an rss file for public consumption would be interested in. The output is formatted such that it will show up as warnings and errors in Xcode's build window if PadCaster is used in a shell script build phase.

To use PadCaster from within NetNewsWire 2,

  • Create a new script-subscription: File > New Special Subscription > Script...
  • Choose PadCaster in the Subscribe to script: sheet.
  • Enter the URL of a MacPAD file in the Args field of the Script Settings pane of the feed info.
  • Change the Type from Applescript to Shell (Perl, Python, etc.).
See this example for reference. Personally, I always forget to change the script type.


Version 1.1, 6/9/2005:
  • Template tweaks.
Version 1.0, 4/16/2005:
  • Initial release.


PadCaster is licensed under this Creative Commons Attribution-NonCommercial license. Source code is available. Contact me if you'd like to arrange to relicense a portion of the code.


Keyword Assistant makes use of Buzz Andersen's very nice NSString+Templating category, which is used under the terms of a Creative Commons license.


Email me at user kenferry, domain

last modified: 4/16/2005