What are some alternatives?
When comparing Blue Crab and FileZilla, you can also consider the following products
HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Cyberduck - A libre FTP, SFTP, WebDAV, S3, Backblaze B2, Azure & OpenStack Swift browser.
DPLOY - An FTP/SFTP deployment tool built in node.js
WinSCP - WinSCP is an open source free SFTP client and FTP client for Windows.
FTPDrive - Download FTP Drive v3. 5. 214 Kb. FTP Drive - program, that allow working with FTP for those programs, that don't know what is FTP. Emulates logical drive, where selected FTP servers are mounted as folders.
Beyond Compare - Beyond Compare allows you to compare files and folders.