deps.ts is currently the most common way, however new projects like fresh use import maps. the problem with importmaps is they are not composable, as such, using an importmap for a library is usually bad as said importmap is not picked up and used, so the end-user would have to add their own importmap with entries compatible for the library (this is what fresh does: it generates an importmap with entries it needs). due to this problem, deps.ts is the most common solution, however I do hope that composability issue with importmaps will change.