What are some alternatives?
When comparing SmartFTP and FileZilla, you can also consider the following products
WinSCP - WinSCP is an open source free SFTP client and FTP client for Windows.
Cyberduck - A libre FTP, SFTP, WebDAV, S3, Backblaze B2, Azure & OpenStack Swift browser.
Beyond Compare - Beyond Compare allows you to compare files and folders.
FireFTP - FireFTP is a free, secure, cross-platform FTP/SFTP client for Waterfox which provides easy and intuitive access to FTP/SFTP servers. You need to download Firefox to install this add-on.
PuTTY - Popular free terminal application. Mostly used as an SSH client.
Forklift - The most advanced dual pane file manager and file transfer client for macOS.