OS X fully supports SMB (Samba) and therefore IPX is included
OS2:
functions of the NetBIOS Kit of TCP/IP V2.0 for OS/2, also known as TCP/NetBIOS.
Linux:
IPX/SPX (Internet Packet Exchange/Sequenced Packet Exchange) is a proprietary protocol stack developed by Novell and based on the Xerox Network Systems (XNS) protocol. IPX/SPX became prominent during the early 1980s as an integral part of Novell, Inc.'s NetWare. NetWare became the de facto standard network operating system (NOS) of first generation LANs. Novell complemented its NOS with a business-oriented application suite and client-side connection utilities.
Linux has a very clean IPX/SPX implementation, allowing it to be configured as an:
* Enable PPP/IPX, allowing a Linux box to act as a PPP server/client
* Perform IPX tunnelling through IP, allowing the connection of two IPX networks through an IP only link
Additionally, Caldera offers commercial support for Novell NetWare under Linux. Caldera provides a fully featured Novell NetWare client built on technology licensed from Novell Corporation. The client provides full client access to Novell 3.x and 4.x fileservers and includes features such as NetWare Directory Service (NDS) and RSA encryption.