I am looking for a term to use as the name of a software project that I am working on.
The project is a software tool, and this tool aims to be useful in virtually all software, so I am looking for a term that alludes to it being an indispensable, or perhaps even the most indispensable, tool in a profession, as in:
- the test screwdriver being the most indispensable item for an electrician
- the monkey wrench being the most indispensable item for a plumber
- scissors being the most indispensable item for a tailor
etc.
A different but equally useful direction of meaning would be a term for an item which is guaranteed to be present in a certain line of business or endeavor. For example:
- In a tire shop they are bound to have lots of tires, so tires are their ___ (fill-in the blank.)
- If there is one thing that mountain-climbers are guaranteed to use, that is rope, so rope is their ___ (fill-in the blank.)
- Every priest is bound to have a bible, so the bible is their ___ (You get the idea.)
Besides the word "indispensable", other terms near the meaning that I am looking for (but unsuitable) are "essential", "sine qua non", "tool of the trade" and "staple item".
I was seriously considering the term "bread and butter", but after reading about it I have formed the impression that it necessarily has a fiscal connotation, while there is none in my case. Please correct me if I am wrong.
(Other than that, "BreadAndButter" would be an awesome software project name, despite being unconventional: the modern trend in software project names is strongly towards unconventionality.)