Blackboard bought out most of their commercial competition (WebCT, Angel) and tried to patent-troll the rest out of business (Desire2Learn for one).
Open-source wise there's Moodle (PHP based) and Sakai (Java based).
But from my POV within higher ed IT, my impression is that many of the big guys (Michigan, Indiana, Cal, NYU, Yale, MIT, Harvard, Stanford) are desperately searching for what's next. edX (Harvard+MIT along with contributions from Stanford) has open-sourced their software, I have no idea if it comes close.
The problem with starting up is that to make anyone happy, a new Learning Management System needs to have two things working spectacularly well:
1. An online testing engine supporting both automated grading and human grading with a wide variety of question types and an easy to use test builder.
2. A gradebook tool that's easy to set up, can import and export spreadsheets, and can support any wild scoring system a faculty member can devise (and they can come up with some doozies). It also needs to integrate with any and every other tool in the system, as some faculty somewhere will want to grade every single type of activity students can perform in the system.
In addition to those two baseline elements it needs a world-class collaboration system for file-sharing, plus messaging and forum tools and online chat. It needs to support multiple class sections with unified resources, ad-hoc class groups, and student-initiated study groups. It needs to support fine-grained permission schemes based on classes, instructors, grad assistants, sections, individual students, and groups.
Every file, test, assignment, forum, and chat room all need to be able to be gated access based on student activity so that, for example, a quiz must be passed before getting access to a document which leads into an assignment followed by a forum-based discussion.
Research is also critical to support, and your system will need to be accessible in a secure way to collaborators, guest instructors, and remotely-enrolled students around the globe, in a way that doesn't make the faculty wait more than a few minutes to grant those people access.
All of this will need to be provided in a fully responsive user interface that scales well from 4k screens down to tablets and smartphones, including the testing and gradebook engines. You'll also need a free mobile app that provides all the same funcionality in a reliable native interface on iOS, Android, Windows Phone, Blackberry OS, and more.
You also need to integrate with the University's student information system, and update enrollments in courses and sections on the fly as students add/drop and courses change, and send grades to the SIS in return. You need to integrate with external tools at the university such as wikis, message boards, and eTextbooks; and outside including cloud-based calendars and document sharing tools including Google Apps for Education and Office365.
You'll also want a instructor evaluation system, electronic portfolio functionality, program-level assurance of learning awareness, institutional assessment reporting, user activity monitoring.
Oh and all of this needs to be customizable to match the traditional way of doing business at each of thousands of different universities. Business processes are not up for compromise.
Notice I've left out concerns of usability, security, performance, stability, ease of deployment and upgrading, etc. That's because those are at the bottom of the list of priorities for the people with the money.
Should point out (since it's not 100% clear in your post) that they -tried- to patent-troll D2L but in the end dropped the case. D2L is still kicking and is in use in a significant chunk of major Canadian universities (including mine).
I've never used Blackboard but I wouldn't ever recommend Moodle as an alternative for anything (and neither would my Java professor to judge by his rants about it...)
I've used Sakai in the past, and Moodle for years now. (I think I used Blackboard once, years ago.) They're all a pain, but it would be hard to hand-code something that has even just the features that I use regularly myself.
That being said, Moodle has some serious issues with dataloss if a user's session times out (and for a long time, the default timeout delay was just 24 minutes). If someone hasn't specifically clicked "Save" or "Submit" before time runs out (even if they were typing constantly the whole time), then those buttons invisibly turn into "Throw away all my work and make me log back in and start from scratch". It's horrific. https://tracker.moodle.org/browse/MDL-11972
My institution uses Moodle, and it mostly works. Except for the first week of term. Except if you pick up a course mid-term. Except if your course uses online quizzes.
As a student, I have no idea how Moodle is from a professor's standpoint, but from a student's it's infinitely preferable to D2L, at least. I've never used Blackboard either, but nobody seems to think that it's appreciably better than D2L, so I doubt Moodle is really that bad in comparison.
Open-source wise there's Moodle (PHP based) and Sakai (Java based).
But from my POV within higher ed IT, my impression is that many of the big guys (Michigan, Indiana, Cal, NYU, Yale, MIT, Harvard, Stanford) are desperately searching for what's next. edX (Harvard+MIT along with contributions from Stanford) has open-sourced their software, I have no idea if it comes close.
The problem with starting up is that to make anyone happy, a new Learning Management System needs to have two things working spectacularly well:
1. An online testing engine supporting both automated grading and human grading with a wide variety of question types and an easy to use test builder.
2. A gradebook tool that's easy to set up, can import and export spreadsheets, and can support any wild scoring system a faculty member can devise (and they can come up with some doozies). It also needs to integrate with any and every other tool in the system, as some faculty somewhere will want to grade every single type of activity students can perform in the system.
In addition to those two baseline elements it needs a world-class collaboration system for file-sharing, plus messaging and forum tools and online chat. It needs to support multiple class sections with unified resources, ad-hoc class groups, and student-initiated study groups. It needs to support fine-grained permission schemes based on classes, instructors, grad assistants, sections, individual students, and groups.
Every file, test, assignment, forum, and chat room all need to be able to be gated access based on student activity so that, for example, a quiz must be passed before getting access to a document which leads into an assignment followed by a forum-based discussion.
Research is also critical to support, and your system will need to be accessible in a secure way to collaborators, guest instructors, and remotely-enrolled students around the globe, in a way that doesn't make the faculty wait more than a few minutes to grant those people access.
All of this will need to be provided in a fully responsive user interface that scales well from 4k screens down to tablets and smartphones, including the testing and gradebook engines. You'll also need a free mobile app that provides all the same funcionality in a reliable native interface on iOS, Android, Windows Phone, Blackberry OS, and more.
You also need to integrate with the University's student information system, and update enrollments in courses and sections on the fly as students add/drop and courses change, and send grades to the SIS in return. You need to integrate with external tools at the university such as wikis, message boards, and eTextbooks; and outside including cloud-based calendars and document sharing tools including Google Apps for Education and Office365.
You'll also want a instructor evaluation system, electronic portfolio functionality, program-level assurance of learning awareness, institutional assessment reporting, user activity monitoring.
Oh and all of this needs to be customizable to match the traditional way of doing business at each of thousands of different universities. Business processes are not up for compromise.
Notice I've left out concerns of usability, security, performance, stability, ease of deployment and upgrading, etc. That's because those are at the bottom of the list of priorities for the people with the money.
So... good luck.