Best places to get open source plugins / instruments?

I’m going to pay for a subscription to Ardour as I have always wanted to get into music production on the PC, but I’ve been relatively constrained by money.

What are the best sites that offer open source VST instruments and effects that will work on Windows 10?

Also if in the future I decide to buy them will the Native Instruments plugins work from within Ardour?

Sorry for the newbie questions but I’ve never used a DAW before.

Here are a couple of starting points:

http://www.reaper.fm/reaplugs/#tour

http://www.reaper.fm/reaplugs/

http://www.airwindows.com/

EQ

https://www.bluecataudio.com/Products/Product_TripleEQ/

Compressor
http://www.audiopluginsforfree.com/rough-rider/

http://www.audiopluginsforfree.com/kotelnikov/

Limiter

Frequency Analyzer

https://www.bluecataudio.com/Products/Product_FreqAnalyst/

Cool. Thanks for the links. I’ll check them out.

It should be noted that many of the plugins listed above (I think all but not sure) are not open source, they are just free (As in beer) plugins.

Bluecat for the record has an entire suite of free (As in beer) plugins that includes the ones mentioned above:

https://www.bluecataudio.com/Products/Bundle_FreewarePack/

I also might suggest looking at the older (But still usable in many cases) mda plugins.

You can always search on KVR as well for free plugins to get many more options, don’t remember them having any way to search for open source, but free as in beer yes.

And of course Ardour comes with the a-* plugins, not VST but will work in Ardour.

       Seablade

I’ve been relatively constrained by money…

Just as with audio hardware, your software audio processing is only as good as the weakest link in the chain.