TrueCrypt
Open Source
TrueCrypt is an open source software to encrypt volumes of data. It even supports the creation of virtual encrypted volumes which is portable.
Boxcryptor
Freemium
Boxcryptor protects your data in the cloud with end-to-end encryption.
EncFS
Open Source
EncFS is a Free (LGPL) FUSE-based cryptographic filesystem. It transparently encrypts files, using an arbitrary directory as storage for the encrypted files.
Compare encfs4win with alternatives
Compare TrueCrypt and encfs4win and decide which is most suitable for you.
Compare Boxcryptor and encfs4win and decide which is most suitable for you.