I am looking for a code snippet manager (or, more generally, a text snippet manager) that stores all of its data locally (i.e. not cloud-based).
As "code snippet managers" seem to cover a variety of use cases, I would like to narrow down the scope: The primary purpose of the application I'm looking for is to organize and let me easily find hard to remember short or long pieces of text. Short can mean that it is just a single word, long can mean that there are 50 or more lines of text. I use most of these pieces of text infrequently and I am not concerned about saving a few keystrokes. In some cases, I would not even want to copy and paste the text anywhere, but just read it right in the snippet manager.
It should be possible to organize code snippets by language/framework/technology (i.e. at least one "hard" level of categorization); anything beyond should be well usable for larger collections of code snippets (maybe by further hierarchical grouping, maybe by user-defined tags, ...). Code snippets must not be limited in length. Syntax-highlighting is a plus, but not absolutely necessary.
The application must run on Windows (although Windows/Linux cross-platform capabilities are a bonus), be gratis and open source, and usable with a GUI (i.e. not a purely text-based interface).
I am not looking for a code editor that also includes a code snippet manager. I am looking for a central tool to store snippets for use in other editors and IDEs.
To emphasize the offline aspect, applications that require me to sign into some online account just to use them are not suitable.