The venerable text editor BBEdit, which has been a staple for many Mac users for 25 years, had just reached version 12. This major update, the first in three years, ensures compatibility with macOS High Sierra, and adds some interesting features, such as the ability to cut, copy, and remove text in columns (delimited by tabs, commas, etc.), a Canonize feature, to perform massive text replacements from a word list, and new display options, including an improved dark theme, something the kids like. (My aging eyes don’t work well with dark themes.)
BBEdit is the tool I use whenever I work on code, or large text files. It’s a powerful text editor that doesn’t suck. If you use it regularly, update now; if not, you should try it out. It costs $50, with upgrades for $30 or $40 depending on how long you’ve owned a previous version.