Unica Acquisti is software that lets public bodies manage their purchasing cycle from planning to payment. It supports multi-year procurement planning, which goes to the national public-contracts hub of Italy's Ministry of Infrastructure and Transport, and the purchase requests raised by departments. Orders are placed directly or through the public-sector e-marketplace Mercato Elettronico della PA. The application connects to the accounting system to check budget and complete invoice payment. It is a Java application with a REST backend, an Angular front end and a PostgreSQL database, meant to be installed on an application server of your own.
Unica Acquisti is maintained by CSI Piemonte, a consortium of public bodies based in Turin, Italy, which is also the copyright holder. The source code is published under the EUPL-1.2, an OSI-approved licence. Because you run the software on your own infrastructure, the data stays with your organisation; no hosted service from the maintainer was found. The package is built around Italian public procurement and is therefore mainly relevant to Italian administrations.