- Mozilla SSL Certs - for corporations that don't want Let's Encrypt
- Mozilla Mail - a reliable Exchange/Google Mail alternative (desperately needed imo)
- Thunderbird for iOS - why is this not a thing yet?
- Mozilla Search - metasearch that isn't based on Bing/DDG/Google
- Mozilla HTTPS DNS - although Cloudflare will probably always do this better
All seemingly low-hanging fruit with brand alignment.