What does MS SQL Server on Linux mean?

I recently took a look at the state of PostgreSQL and C# and reveled in the maturity of the tooling around it.  Now, I want to think about what Installing SQL Server on Ubuntu means.  For a long time, if I thought of Enterprise, Linux, and Databases together in a single thought the only things that came to mind were Oracle or PostgreSQL.  I know that I am doing a disservice to MySQL and a ton of other solid relational databases, but that is what I knew.  I won't even mention MongoDB or the other NoSQL databases because they fill a different niche.  Now, I have to add MS SQL Server to the mix.  What does it look like?  How do you manage it?  Are there any differences that we need to take into consideration when we program against it?  What is the update story?  Will it support running SharePoint?!?!  Those are questions I hope to answer over the coming weeks as I start yet another series of articles.