Based on our record, WinCompose seems to be a lot more popular than Holdkey. While we know about 16 links to WinCompose, we've tracked only 1 mention of Holdkey. We are tracking product recommendations and mentions on Reddit, HackerNews and some other platforms. They can help you identify which product is more popular and what people think of it.
I used Holdkey for a while because I needed so many special characters. Not sure it's a good solution for em-dashes though. - Source: Reddit / 3 months ago
Another similar program is WinCompose, but instead of holding down WIN+ALT and pressing a key, one presses the RIGHT ALT key and types a sequence. For instance, I have Greek letters bound to RIGHT ALT, G, [corresponding Latin letter], script letters bound to RIGHT ALT, Q, [corresponding letter], blackboard bold bound to RIGHT ALT, |, [corresponding letter], Japanese kana bound to RIGHT ALT, J, [syllable in... - Source: Reddit / about 14 hours ago
WinCompose is also pretty great, it has all the shortcuts predefined for you. https://github.com/samhocevar/wincompose/ I don't know how LaTeX works so this might not be what you're looking for. - Source: Reddit / 13 days ago
Right-Ctrl C ' if you have a compose key (built in on Linux, WinCompose for Windows, no clue for Mac).  https://github.com/samhocevar/wincompose. - Source: Hacker News / 19 days ago
A couple of years ago when searching for an easier way to enter special characters, I lucked into común across a program called WinCompose. It's light on system resources and simple to use. I can't say enough good things about it. - Source: Reddit / 20 days ago
I almost entirely agree, though I think your third point (typing non-ascii characters) could be less severe with one extra lesson in the typing course most kids are forced to take. When I first took French in 7th grade somehow I learned online you could enter ascii codes (whatever those were) on Windows with alt+numpad, and I still have memorized that alt+130 gives é. Later I moved to Linux where we have a great... - Source: Hacker News / about 2 months ago
PopChar - The character map that works!
SymbSearch - A tool for searching unicode-symbols and copying it to the clipboard.
Event Viewer - Get help, support, and tutorials for Windows products—Windows 10, Windows 8.1, Windows 7, and Windows 10 Mobile.
WizKey - WizKey makes it easy to type accented and other special Unicode characters using a standard US/UK keyboard with easy to remember keyboard shortcuts.
BabelMap - Unicode Character Map for Windows
Gucharmap - Open source character map for the GNOME desktop environment.