The review system Gerrit is used together with a Git repository, how you obtain it in Cusy together with Gitblit.
With Gerrit the changes are not passed directly to a Git repository, but instead sent to Gerrit. There, the changes can be discussed and improved changes are uploaded. Each Patch-Set can be tuned individually, then these changes are taken together in the Git repository.
Gerrit is used by many major IT companies such as Android, Intel, Red Hat and SAP. However, it is also used in open source projects such as LibreOffice, MediaWiki and the Qt framework.
Gerrit is licensed as free software under the Apache License 2.0.