Xircom Incorporated was one of the earliest major players in networking components and accessories, and from their pioneering debut in 1988 to their successful purchase by Intel in 2001 they were consistently regarded as being one of the few companies serving the needs of mobile computing users accurately and well.
Xircom's main claim to fame is that they were ahead of the bell curve on almost every major networking technology in use today. Xircom's earliest product was a LAN adapter that connected through the parallel port dedicated to printers - then the only universal port on notebook PCs. This device singlehandedly launched the mobile networking market, which given its current status as a ubiquitous multibillion-dollar industry is remarkable. Following up on their innovative success came their RealPort line of PC network cards. Before RealPort, most network cards still relied on pop-out Ethernet jacks and additional dongles and breakout boxes to achieve connectivity. By integrating those connectors directly on the card, Xircom became the first major market device that could easily and securely attach an Ethernet cable from a PC to a switch. They followed this up in 1994 with a number of devices that failed spectacularly, attempting to work with a new IEEE technology called "wireless LAN" - and while they were ahead of their time and speeds weren't up to par, they produced the earliest known wireless print server and several early wireless routers and PCI cards. When you consider that the dominant form of Internet hardware in 1994 was the 28.8kbps modem, this is pretty incredible.
In addition to their successful line of RealPort cards, switches, and routers, Xircom also dabbled in the PDA market and the USB PCI card market during the early days of USB adoption and conversion. Other projects included CompactFlash card readers and numerous PCMCIA cards that emulated many of their successful projects, including their vaunted "CreditCard" GSM adapters, one of the earliest precursors to cellular modem connectivity. They were also an early innovator of Bluetooth technology, promoting it on a number of their network cards.
After their purchase in 2001, their products were essentially left alone by Intel, but all further products were released under Intel brands, and the last of the line was discontinued in 2005. Many of Xircom's engineers continue to work for Intel today, including their founder Dirk Gates who now serves as the company's Vice President of Mobile Communications.