makeself is a small shell script that generates a self-extractable compressed TAR archive from a directory. The resulting file appears as a shell script, and can be launched as is. The archive will then uncompress itself to a temporary directory and an arbitrary command will be executed (for example, an installation script). This is pretty similar to archives generated with WinZip Self-Extractor in the Windows world.
UnZip will list, test, or extract files from a ZIP archive, commonly found on DOS and Windows systems. A companion program, Zip, creates ZIP archives; both are part of the Info-ZIP project. Both programs are compatible with archives created by PKWARE's PKZIP or Nico Mak's WinZip, but in many cases the program options or default behaviors differ.
Zip is a compression and file packaging utility for Unix, VMS, DOS, OS/2, Windows 9x/NT, Amiga, Atari, Macintosh, BeOS, SMS/QDOS, MVS, VM/CMS, and others. It is analogous to a combination of the Unix commands tar(1) and compress(1) and is compatible with PKWARE's PKZIP and Nico Mak's WinZip. It's part of the Info-ZIP project.
pkt is a universal XML packet archiver. It can manipulate files for backing up documents, transferring them across networks, emailing them, and sharing them by other means (p2p etc). It uses plugin filters to do the job and handles virtually any format available if there is a plugin for it. It handles encryption, compression, conversion, parity checking, decryption, decoding, repairing, rebuilding, and other tasks using a universal file format (XML-based). By default, all pkt output is in 7-bit ASCII which is UTF encoded and is compatible with XML parsers. pkt files can be disassembled, reassembled, and repaired by hand if necessary. pkt also supports the use of 8-bit compressed XML packets for its archives using one of several compression algorithms. In general, pkt will try to use the best algorithms available.