System_Log is an Ada binding to the Unix syslog functions. It lets you send log messages to the system log from your Ada program.
The source is available as releases and in a public Git repository.
There is documentation in the form of comments in the package specification.
In addition to those you may want to read the manual page for syslog,
which you should get with the command man 3 syslog on any
Unix-like system.
System_Log is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License version 3, as published by the Free Software Foundation.