Portugal eID Card Middleware

The Portugal eID Card Middleware is a software package for Desktop computers: Windows, MacOS and Linux  that provide access to all the eID functionality of the Citizen Card, namely identification data, authentication and digital signatures.
Additionally it provides access to newer eGov services like Professional Attributes Signature and soon it will have a new signature feature that doesn't require the physical card and card reader:
Chave Móvel Digital.
The software is made available by the public agency AMA at: https://www.autenticacao.gov.pt/cc-aplicacao
All the source code and API documentation is available for developers at: https://svn.gov.pt/projects/ccidadao