Performance:

- for scrollback, investigate using segmented list for sufficiently large
  scrollback scenarios.
- Loading fonts on startups should probably happen in multiple threads
- `deleteLines` is very, very slow which makes scroll region benchmarks terrible

Correctness:

- test wrap against wraptest: https://github.com/mattiase/wraptest
  - automate this in some way
- Charsets: UTF-8 vs. ASCII mode
  - we only support UTF-8 input right now
  - need fallback glyphs if they're not supported
  - can effect a crash using `vttest` menu `3 10` since it tries to parse
    ASCII as UTF-8.

Improvements:

- scrollback: configurable

Mac:

- Preferences window

Major Features:

- Bell
- Sixels: https://saitoha.github.io/libsixel/
