OpenPass is a method for data recording on RFID card in an integrated access control system, with proprietary software by different providers.
OpenPass is released under the GPL license.
The OpenPass system.
The OpenPass system consist of:
To allow the exchange of information between heterogeneous access control systems, OpenPass defines an interchange format through the use of metalanguage XML. Access credentials are stored on the smartcard and organized through the use of markers, represented in XML. The XML representations are made public by the server OpenPass. 
With a single RFID card, the user access to all sites in the system: each company is able to issue the ticket yourself and the card is recognized by every member of the system independently.
The OpenPass standard defines a distributed network of data centers, that are web service connected with the server. The information collected by data centers regarding sales and passages to the gates and they are sent to the central server. The exchange format between server and collection centers is XML. 
The OpenPass server receives the data and stores them in a centralized SQL database, where each data item is related to a UID and any personal details of the customer.
Highlights of OpenPass.
The methodology OpenPass is characterized by:
OpenPass projects.
For now, OpenPass is applied to control systems access to the ski lifts, in Italy and France:
Italy: Skipass Lombardia.
Skipass Lombardia was the first example in Europe of open standard for integrated access control systems with heterogeneous and proprietary software. OpenPass has created an integrated system for all companies of skilifts in the Lombardy Region: 310 ski lifts, 46 companies in 30 ski areas.
France: Nordic Pass Rhône Alpes.
The Federation of Nordic skiing in the French region of Rhône-Alpes (FRAN) has promoted the Nordic Pass Rhône Alpes: a project of integrated access to 5000 km of ski runs in 83 stations of Nordic skiing, with OpenPass standard.
Italy: SkiArea VCO.
In the Alps of Piedmont, Neveazzurra ski resort has implemented SkiArea VCO: a project of integrated access to the stations of Neveazzurra resort: Alpe Devero, Antrona Cheggio, Ceppo Morelli, Domobianca (Domodossola), Druogno, Formazza, Macugnaga, Mottarone, Piana di Vigezio, Pian di Sole, San Domenico (Varzo).