From the included Version 2.0 - March 23, 2011 changelog, to quote:
Moved to a different XMB category (now under Network)
Fixed another possible memory leak
Added "dev_dragon" to mount detection and warning list
Changed LIST command output format (again)
Added new algorithms and methods
Should support Remote Play (untested)
Added a better way to get the IP (no internet required anymore - thanks andoma)
Added /app_home and /host_root to listing exceptions as they cause problems
Now uses Hermes' sysfs sprx link instead of lv2 syscalls
Tweaks made to improve internal performance, stability, and reliability
Added a "screen saver" (simply blanks screen after 60 sec of no controller input)
Added an exit application button combination shortcut (SELECT + START)
Added an internal "retry system" designed to reduce failed transfers for small files
New git for v2.0 and later: http://git-hacks.com/openps3ftp
General Usage Tutorial : Just a small tutorial on the basics.
Custom Firmware (tested on 3.55, but should work for all)
A network connection
Extract the pkg files from the archive and copy them into a USB drive
Connect the USB drive to your console and select the pkg file under the "Install Package Files" menu (found under Game)
Note: The pkg file that you select should correspond to the custom firmware you are using. For example: if you have installed geohot's 3.55 jailbreak, use the file "openps3ftp.geohot.pkg". If not, use "openps3ftp.pkg". Users of CFW 3.55 kmeaw can use any pkg.
OpenPS3FTP is now installed!
Launch OpenPS3FTP (found under Network)
Wait until you see text on the screen.
Connect to your console using an FTP client (such as FileZilla) with the IP address and port shown on the screen with user root and password openbox.
Now that you're connected, you can browse through and manipulate files on your console as if it were a folder on your computer.
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.