Thanks for your interest in the development of Delphes.
The Delphes development model is community-based. Users willing to participate are encouraged to fork Delphes Git repository and to submit pull requests for improvements and bug fixes. The Delphes core development team from the CP3 centre of the Université catholique de Louvain is in charge of the maintenance, releases, and general support to users via the ticket system.
Questions, suggestions and bug reports can be made through the ticket system available on our website. After checking that the issue is not already being adressed, you can create a new ticket. Note that you will have to register first.
Documentation is collected in the Workbook.
A good starting point is the Quick Tour.
More details can be found on the Delphes website.