The EDA ecosystem is a collection of independent EDA related tools. The tools work together to some degree. The development of the ecosystem is very loosely coordinated.
For the good old UNIX traditions: have a set of tools that each concentrate on one job and can be connected. This helps keeping the tools small and simple and makes them replaceable.
As a developer of a tool that tries to solve one part of the problem properly, the ecosystem offers the rest of the toolchain your users will need. For example if you have a fine schematics capture software, the ecosystem would offer your users a PCB layout tool or a cloud library of symbols/parts/data that can be used with your software out of the box.
The ecosystem model has two rings or tiers, a tight and a loose. In the tight tier, tools have to spend some development time on implementing interfaces (mainly file format support) so they can communicate to other software in the ecosystem. We have a format designed specifically to make this process as cheap as possible.
In the loose tier, you don't need to do much, your tool is dragged into the ecosystem by other tools being able to communicate to it.
No. You can join while being part of other efforts. A whole EDA suite or random parts of it can also join. The idea is that the ecosystem provides a group of tools that work together - it doesn't affect other aspects of the tools.
Drop me a mail at ecosys [at] igor2.repo.hu or visit our IRC channel.