Matt Groening wrote:
I have questions about the API compatibility.Let's say I develop an Addin for SW 2017. Is it backward compatible to older Versions?
If you are careful and don't use any functionality that was added in 2017 that doesn't exist in earlier versions.
Are Addins for older version upward compatible?
Usually, unless some API call you are using has been obsoleted.
The API docs clearly indicate the obsolete stuff and also list what version any particular API function was added. If you want to be safe, use the API docs from the oldest SW version used by your target users, and test everything heavily with all newer versions.
I'm still on 2012 and developing macros. There have been a couple of places where I've hit a wall that could be surmounted with an upgrade to 2017. It looks like the API developers are in the habit of incrementing and obsoleting old API calls as they change them or fix bugs. I think the safest way to develop a backwards compatible macro would be to do it with a modern 2017/(2018 !?) installation but limiting yourself to the 2012 section of the API documentation (or whatever year you want to travel back to).