Similar to CURL

Elasticsearch

EGS (program)

Embedded GLIBC

Enlightened Sound Daemon

Erlang (programming language)

ERP5

Mule (software)

Etherpad

Exa (command-line utility)

Exaile

EZ Publish

F-Spot

Far Manager

Fetchmail

Fastest Fourier Transform in the West

FindBugs

Firebird (database server)

Firestarter (firewall)

Flask (web framework)

FLTK

Flutter (software)

FMSX

Foliate (software)