Over the past year I've been working on a 2.x branch for the Purge module. It will be a major upgrade from the 1.x series and will make giant leaps in human and technical usability. These new functionality will not be backported to 1.x by me but I welcome patches to improve it. A bugfix release of the 1.x branch will follow at some point but scarse development time will be put into the new branch first.
Configuration storage in variables. (95% done)
The individual proxy configurations are stored as serialized objects in a Drupal variable. This allows for a great many extra options without the hackish proxy url scheme. Individual proxy configuration allow for adding custom domains and headers and settings advanced options like parallel execution and nonblocking requests. You can easily combine multiple proxy configurations. Also removes the configuration size limits imposed by the 1.x scheme improving scalability.
Todo: upgrade from 1.x, system and template configurations.
Admin Gui. (80% done)
The spartian configuration by the non intuitive proxy URL scheme wil be replaced by a spiffy gui that allows to edit proxy configurations through detailed forms.
Dependencies and integration (90% done)
Purge 2.x will have no dependencies. The Expire module integration is now optional. The dependency on the Curl library is dropped by adding support for the Httprl module and the native drupal_http_request. All these will have options to send purge requests one at a time. Curl and Httprl can issue requests in parallel. Httprl can issue nonblocking requests.
API to allow other contrib modules to interact with Purge. (80% done)
- Auto discovery of certain purge enabled platform. (doable for Acquia platforms).
- Adding extra domains, headers and form elements for more platforms. (like fastly)
Documentation and inline help. (10% done)
Readme.txt should be updated, as well as the Project page, the Varnish documentation handbook pages. May end up adding advanced help.
Q2 2014 update: I've adapted the description above. Rewrote most of the code into a more OO module. It has been stabilizing over the past few weeks. Dev releases are still unstable but can be informative to the curious.