EndNote is a widespread and powerful system for Windows and Macintosh with a good Microsoft Word integration. References can be synchronized and accessed on the web.
Producer
Clarivate Analytics (formerly the Intellectual Property & Science business of Thomson Reuters)
Usage: single user, desktop based / multi user, web based
Limit: no limit on the number of references but it is recommended that it does not exceed 100.000 references on the desktop version to maintain efficient performance managing the database; 50.000 references on the web version
Using EndNote Web (cloud syncing) the data are saved with Amazon Web Services in Europe and may be replicated in more than one European regions for redundancy.
Documentation
Reference Management with EndNote, an overview (Sabine Schneider, MPI Biochemie)
The "Find Full Text" feature offers the possibility to download large numbers of full text automatically. This feature may cause problems concerning the licence contracts between the publishers and the MPG. Please notice the General Access Conditions