Is there a noun that denotes "things which exist"? The only noun form of existence that I can find/think of is "existence" which is the condition of existing, not the things which do.
It's to summarize the tools for a given task that already exist, in a presentation outline (so it needs to be a single word, but I can't give an example sentence!). The other headings are RCA/Techniques/Lacunae.
ETA: Beings implies a certain amount of animacy, which these things definitely don't have.