UPDATE:
This answer is relevant for old versions of Rebex FTP released BEFORE 2012. Starting with version Release 2012 R1 there is only one version of Rebex ftp dll.
Short answer:
If you need both FTP and FTP/SSL use the Rebex.Net.Ftp.dll from "Rebex FTP/SSL" installation package.
Longer answer:
Rebex.Net.Ftp.dll from "Rebex FTP"
- depends only on
Rebex.Net.ProxySocket.dll
- supports plain FTP
Rebex.Net.Ftp.dll from "Rebex FTP/SSL"
- depends on
Rebex.Net.ProxySocket.dll
, Rebex.Net.SecureSocket.dll
and Rebex.Security.dll
- supports plain FTP
- supports FTP over TLS/SSL channel