The more specific they are (to something you care about) the better.
Unless they're so general that there are high-quality talks about a range of things I suppose.
ABAP will always hold a special, quirky little place in my heart. It's very powerful, but also totally frustrating. The language is a COBOL-like language made by Germans with a keyword graveyard as big as Berlin. The ABAP community (in my experience, online and offline) is totally unacademic: algorithmic complexity is a foreign concept, "code clarity" meant "hitting the Pretty Printer button every few years" (which was a nice feature), and there's no remote concept of best practices.
On the bright side, it makes for a good income, and the debugger is a gem.
The only advantage that I see is that for the most part, every program will look almost the same regarding standard SAP tables.
For example, they had their own language that abstracts and operates directly over a database. They had their own drag and drop UI builder, that compiles down to a HTML page or a desktop widget - which is again not an ordinary feat. They view code as data, as in even the UI is stored as a configuration and not as some Java code. They had their own VCS back when Git didn’t exist. Of course, all these weren’t best of their class, but they sure did get there ideas right.
All these must have been interesting engineering concepts back during its time, yet there hasn’t been much tech literature on how they accomplished it or what inspired them to. At least not that I know of.
Now that open source is on fire, of course a single company cannot catch up with the pace these open source softwares are racing ahead.
Companies like Zoho and Salesforce are able to catch up because they do two things right.
#1. Cloud
#2. Adopting open-source and making a clever mix of proprietary engineering
The next SAP or Oracle will certainly be companies that get those two things right.
SAP right now is making a move on cloud using SCP and as open source goes, openUI5 exists.
I don't have much to say about SCP, just that the company I'm on decided to not use it, basically because we don't see advantages and to avoid future lock-ins
About openUI5, I honestly dislike it, the most useful features of that framework are locked inside SAPUI5(a supersetof openUI5) and pull requests are managed by a branch of the company itself and they are pretty harsh on it. SAP documentation on it can be bad and is entirely biased towards deploying things inside SAP or SCP, which is pretty annoying