It may be obvious, but all of these utilites are themselves compressed in either the Binhex or Macbinary format (with either the .hqx or .bin extension) so they assume you already have a copy of Stuffit Expander, which will decode these formats. Most browsers come with a copy of this tool included.

StuffIt Expander - .sit/.hqx/.uue Decoder

StuffIt Lite - .sit/.hqx Encoder/Decoder

MacBinary II+ - .bin Decoder

MacBinary II+ is really no longer necessary, since Stuffit Expander already can decode this format, but I put this link here anyway since some old error messages mention that you need this tool, and people often ask for it.

BinHex 4.0

DD Expand - DiskDoubler Decoder

DiskCopy - .image Extractor

MacCompress - Unix .Z Decoder

TAR - Unix .tar Decoder

SunTAR - Unix .tar Decoder

UNSHAR - Unix .shar Decoder

Compact Pro - .cpt Encoder/Decoder

ZipIt - .zip Encoder/Decoder

MacGzip - GNU .gz Encoder/Decoder

MPack - MIME Decoder

UULite - uuencode .uue Decoder

UUCD - uuencode .uue & Base64 Decoder

YA-Base64 - Base64 Decoder

DeArj - .arj Decoder

MacZOO - .zoo Decoder

ArcMac - .arc Decoder

MacLHA - .LHA Encoder/Decoder

MacROT13 - ROT13 Decoder

The Cross-Platform Page - Compression Formats