How much work is plugin compatibility?

[Trond]

I am making a program with plugins and I am wondering about how compatible the plugins should be across changes in (additions to) the plugin interface (for new versions of the program).

Obviously, the more compatible the better, but also it's more work.

All plugins can be used with all version of the program
Extra work in both the main program and the plugins.

Older plugins can be used with newer program but not the other way around
Some extra work, but only in the main program (plugin writers will not have to concern themselves with it).

Newer plugins can be used with older program but not the other way around
Only extra work for the plugin writer (not a good option).

Only plugins which were made to use the same plugin interface as the main program are compatible
Easy to program.

[dracflamloc]

Definitely Older plugins can be used with newer program but not the other way around.

One of the only gripes I have with firefox is how when they release a new version I don't use it because the plugins don't work.

[dell_jockey]

it all depends on how many plugins are going to be there, and how many versions of these plugins you want to maintain. Also, are third parties going to write plugins that use your plugin API?

I voted for the last option, as this makes the logistics of deploying your app more manageable.

[dracflamloc]

I would split it. So that major version releases like 1.0->2.0->3.0 don't feature any backward compabiliity, but minor releases like 1.1->1.2 etc should be backward compatible.

[Trond]

I have decided to at first go for only plugins that are perfectly compatible will be accepted. Maybe I'll change it later.

Note that this won't be like Firefox because I don't plan to change the interface, and it's the actual interface that is checked, not the program version as with Firefox.

Edit: But keep voting.

[SimpleMind]

Can I see a plug in as an ActiveX component?