This module attempts to provide a compatibility layer between the old CiviCRM 1.0 API and the new CiviCRM 2.0/3.0 API.
Only install this module if you are using CiviCRM 2.0+ and if a CiviCRM module depends on it.
The module is currently seeking a maintainer who can bring it to a stable release (see below). As I have outlined in #816366: Seeking new maintainer, I am not certain it is still necessary.
It is being used by the civinode (see #230103) module. It was also being used by the send module, but, to the best of my knowledge, it is not anymore. It is not used by the new 6.x version of the CiviCRM Subscribe module.
If you know of other modules depending on this module, please add them to this list: #922748: Create complete list of modules depending on this module (both in 5.x & 6.x), and I will add them to the project page, and advise them to upgrade their code to use the new CiviCRM API.
Seeking new maintainer
Since this module will no longer be needed by the 6.x branch of the CiviCRM Subscribe, and I no longer have any sites running 5.x, I don't have a compelling personal reason for working on it, and thus am seeking a maintainer who needs to use it for compatibility with CiviNode or another module, and so is in a better position to test patches.