Tested on PS3 firmware 3.55, but should work for any firmware.
CHMOD (file permission setting)
Almost all FTP commands are supported
1.1 - stability, performance, and bugfix
1.2 - passive mode bugfix and other stuff
1.3 - REALLY BIG AND AWESOME UPDATE
1.4 - The finale
1.5 - Encore
2.0 - fresh start - as of version 2.0, OpenPS3FTP is located under Network.
2.1 - minor improvements
2.1.1 - more improvements and major fix
2.2 - rewrite for psl1ght v2 + fixes - as of version 2.2, any password is accepted by default.
Stay tuned for more PS3 Hacks and PS3 CFW news, follow us on Twitter and be sure to drop by the PS3 Hacks and PS3 Custom Firmware Forums for the latest PlayStation 3 scene updates and homebrew releases!
To quote, roughly translated: CHANGELOG OPENPS3FTP 3.1 (OPS3PS3FT31.pkg)
Fixed data connections
Removed unnecessary checks.
Use O2 instead
Compatible with 4.46 LDZ FERROX/HABIB
Improved Speed Transfer
Fixed minor bug cfw 4.46
(may still have some bugs, please report.)
Update: From jjolano: OpenPS3FTP is an open source FTP server for the PlayStation 3. It supports the basic FTP commands that the typical user would need to transfer files in and out of their console. OpenPS3FTP is built using libraries from the PSL1GHT SDK (commit 534e589).
Release Candidate 4:
Minimizing use of string streams
Added more information in README.txt and ChangeLog.txt
Fixed a few errors and potential bugs from previous release candidates
Shifted some code around
Includes DEX build
Release Candidate 3:
Fixed polling events
Release Candidate 2:
Fixes some issues in data connection handling.
Some unnecessary code removed.