There are many free and commercial LMS solutions available (see for example, the list of LMS on Wikipedia: https://en.wikipedia.org/wiki/List_of_learning_management_systems), but perhaps the most widely used and richly functional LMS is Moodle (https://moodle.org/), which is free and OpenSource - Moodle is used by probably the largest number of educational and training institutes around the world with just under 180,000 sites at present and with over 300 million users globally - Moodle LMS is the standard for many UK and International Universities.
Drumlin secure PDF files (drmz files) are fully compatible with Moodle solutions, but of course can be provided on any LMS, so the use of the Drumlin Digital Rights Management (DRM) service and Javelin3 readers works just fine with files hosted on a Moodle or any other LMS platform, and we are happy to assist with advice on this if required. Likewise, with Webdoxx web-based secured files (PDF, PPT or ePUB) files may be hosted remotely and accessed via links or iframes from the Moodle hosting server. In general LMS solutions do not provide content security, i.e. features like copy protection, print controls, watermarking, download protection etc. are not provided at the same level as with a DRM service.
Moodle can be set up and installed on your own servers by your own IT team, but if this is not what you want and/or you decide you need tailoring or third party hosting, there are a huge number of Moodle support organizations globally (certified Moodle partners). Another option is to use the existing Moodle Cloud service (https://moodle.com/solutions/moodlecloud/) where they provide the hosting for you, with a pre-built or customized LMS solution.