Was today directed to a nice little site giving the differences between different database systems. Its a nice succinct table of features
There is however an issue having yes and no answers to many of the features. A lot of them are grey, i.e. in SQL server you don’t have before triggers but you have instead of triggers.
The problem with this is also it gets out of date quickly. Although the fact that SQL Server has had user defined types based on CLR for almost a decade suggests the writer isn’t a SQL Server person.
It also believes that you can’t return the results of an OUTPUT clause as a result set.
So as with much content on the web, take it as guidance but if you are really looking for a feature then go check the relevant forums/official documentation.