TrueCrypt is an open source software to encrypt volumes of data. It even supports the creation of virtual encrypted volumes which is portable. Developed by TrueCrypt Foundation
License: Open Source
DiskCryptor is known for its advanced encryption capabilities and support for full disk and removable drive encryption, while TrueCrypt is recognized for its user-friendly interface and the ability to create hidden volumes. However, TrueCrypt's development has been discontinued, which raises security concerns, while DiskCryptor may be less user-friendly.