Gardeners, smallholders and farmers used to breed varieties. Now such people operating outside plant breeding stations are so rare they get a special name, freelancers! Examples are documented by Carol Deppe (2021).
Most freelancers have a limited aim, for example, a local or organic need or a specialist cooking purpose. Most also act individually.

The Dwarf Tomato Project, led by Craig LeHoullier in the USA and Patrina Nuske Small in Australia is unusual because it demonstrates freelancers collaborating amongst themselves. And this collaboration has enabled it to be amazingly successful.
They started chatting via a website in 2005 about the unsuitability of heirloom tomatoes for growing on a patio. A specially-created website called Tomatoville brought together more enthusiasts.
They were an ocean apart but they all wanted to convert their tall heirloom tomatoes into dwarf, but still tasty, varieties suitable for growing in pots on a patio.
As a result of being in different hemispheres (USA & Canada versus Australia & New Zealand), they could shuttle seeds from one hemisphere to the other and get two growing seasons in one year! And they released their first varieties just 5 years later, in 2010!
Over 100 dwarf tomato varieties have since been created including Iditarod Red shown opposite. Several are sold by national seed retailers; all come under the Open Source Seed Initiative (OSSI) which ‘preserves the rights of farmers, gardeners and breeders to freely use, save, replant and improve seed of OSSI-Pledged material’.
There are now websites specifically aimed at facilitating electronic collaboration amongst freelancers. One is the Experimental Farm Network. This has dozens of projects on its site.
The following one is a sample:
‘Selecting the best genetics of landrace watermelon and citron melons for Northern Colorado, USA. Looking for unique traits such as deep citron roots that thrive
in poor soil, drought adaption, yellow ripening genetics, sweet domestic watermelon flesh, and possibly winter storage watermelons that keep 3-6 months.’
Credit: Experimental Farm Project (https://www.experimentalfarmnetwork.org)