Free And Open source File Encryption Tools

AES Crypt
AES Crypt is a free and open source file encryption tool. It supported cross platform like Windows, OSX, Linux. It is very easy to use file encryption tool. It also supported command line interface to secure the file. AES Crypt limit you to encrypt individual file however you can encrypt several file at time by creating zip file and encrypted them. Encrypted file cannot see every one because it is secured with password. It used 256-bit encryption algorithm you can safely secure your most sensitive files. Since it is open source it provide the publicly open source code. You have a freedom to modify the AES Crypt according to your need. You can used it in your office free of cost because it is free and open source tool.
AxCrypt
AxCrypt is also an open source file encryption tool for Windows. You can use it in Window and perform multiple function like encrypt and decrypt, compress and store, work and send files individually. It is very easy to use software tool and used key file instead of a passphrase. Keyfile is more secure encryption method as compare to passphrase. It is also a single-file encryption program. You can use this tool on Dropbox, Google Drive, Live Mesh, SkyDrive and Box.net for security purpose. Most useful features provided by AxCrypt are protect number of file using strong encryption password, right click integration with Windows Explore,it is easy to open, edit and save protected files,easy installation,AxCrypt is translated into different languages.
DiskCryptor
DiskCryptor is an open source software solution for full disk encryption. It use AES 256, Twofish, and Serpent encryption algorithms. It use key file for security instead of password. Since it is full disk encryption tool it enable you to encrypt hard drives, or partitions, has the ability to encrypt the partition and disk on which Windows is already install and supported disk devices with large size. It automatically mounted external USB flash drives and other removable volumes. It also supported different multi boots option and full compatible with third party boot loaders. It supported key file and provide option to boot an external media and to authenticate using the key media. It released under license GNU GPLv3.
EncFS
EncFS is an open source software solution for file encryption. It is very easy to use encryption tool which used an arbitrary directory as storage for the encrypted files. It use AES_256,Cipher encryption algorithm and supported cross platform like Linux, FreeBSD, Mac,Windows, Andorid. It use volume key for file encryption and password is use to decrypt key,EncFS’s volumes is not occupy a fixed size,size can be increased and decreased by adding or removing files. It also encrypted file individually and very useful for cloud storage security. EncFS utilize bitrot detection functionality for underlying file system. It released under license LGPL.