Port 178 carries the NextStep Window Server protocol. On paper, it's just a display server for NeXT computers—the workstations Steve Jobs built after Apple forced him out in 1985. But one of those machines at CERN became the cradle of the World Wide Web. Every pixel Tim Berners-Lee saw while writing the first web browser in 1990 was rendered through this protocol.12
What NextStep Window Server Does
NextStep Window Server is the display system for NeXTSTEP, the operating system that ran on NeXT computers. It handles everything you see on screen: windows, buttons, text, graphics. Port 178 is how applications talk to the window server—requesting screen space, drawing graphics, responding to mouse clicks and keyboard input.
What made it remarkable was Display PostScript. While other systems in the late 1980s drew graphics using crude bitmaps, NeXT licensed Adobe's PostScript language as its display engine.3 Everything on screen—from window title bars to application graphics—was rendered using the same PostScript commands that professional printers used. Vector graphics. Scalable fonts. What you saw on screen matched what came out of the printer, pixel for pixel.
The window server consumed 3-4 MB of RAM just running idle, which was enormous in 1988. But it meant every NeXT application had access to professional-grade graphics without writing rendering code.4
The Machine That Created the Web
In September 1990, Tim Berners-Lee sat down at a NeXT Computer at CERN in Switzerland. He was trying to solve a problem: scientists around the world needed to share documents, but every computer system was incompatible. He had an idea for a universal documentation system—pages linked together, accessible from anywhere.
The NeXT gave him something most workstations didn't: an object-oriented development environment that let him prototype quickly. Within two months, he had written both the first web server (CERN httpd) and the first web browser (WorldWideWeb). Both ran on NeXTSTEP.56
Every line of HTML he typed appeared through the NextStep Window Server on port 178. Every hyperlink he clicked—the first hyperlinks anyone ever clicked—traveled through this display protocol. The window showing the first web page in history was rendered via port 178.
Tim Berners-Lee later credited NeXT's development tools for making the Web possible so quickly. "I could do in a couple of months what would take more than a year on other platforms," he said.7 The combination of object-oriented programming, Display PostScript, and Interface Builder let him focus on the concept rather than fighting with graphics code.
In December 1990, he put the first web server online. The NeXT Computer's label read: "This machine is a server. DO NOT POWER IT DOWN!!" Port 80 carried the Web. Port 178 carried the display that showed it being built.
The NeXT Legacy
NeXT computers never sold well. They were expensive—$6,500 base price in 1989—and Steve Jobs' company struggled commercially.8 But the technology was years ahead of everything else. Besides inventing the Web, NeXTSTEP was where id Software developed Doom and Quake, defining 3D gaming.
In 1996, Apple bought NeXT for $427 million, primarily to acquire NeXTSTEP.9 Steve Jobs returned to Apple. NeXTSTEP became the foundation for Mac OS X, which evolved into macOS, which spawned iOS, iPadOS, watchOS, and tvOS. The window server architecture that ran on port 178 became the ancestor of every display system on every Apple device today.
Port 178 itself faded into history. Few NeXT machines remain running. The protocol is obsolete. But for a brief moment in 1990, this port carried something irreplaceable: the view of the World Wide Web being born.
Modern Usage
Port 178 is officially assigned to NextStep Window Server in IANA's registry, but it's essentially unused today.10 NeXT computers have been obsolete for over two decades. Occasionally, you'll find port 178 listed in old network documentation or legacy firewall rules that nobody remembers the reason for.
Some security databases flag port 178 because malware has occasionally repurposed abandoned well-known ports for command and control traffic. If you see port 178 active on a modern system, it's probably not a NeXT computer—it's either misconfigured software or something suspicious.
To check what's listening on port 178:
Linux/Mac:
Windows:
On any system built after 2000, you should find nothing.
The Well-Known Ports Range
Port 178 lives in the well-known ports range (0-1023), also called system ports. These ports require root or administrator privileges to bind to, and they're reserved for standard Internet services assigned by IANA. Port 80 for HTTP. Port 443 for HTTPS. Port 22 for SSH.
Port 178 belongs to this exclusive club—not because NextStep Window Server became a standard Internet service, but because in 1988, when NeXT registered it, IANA gave out well-known port numbers more freely. The registry wasn't as crowded. Nobody imagined we'd run out of numbers below 1024.
Most well-known ports have stories like this. They're fossils of computing history. Some carry protocols everyone uses daily. Others, like port 178, carried something once and now serve as monuments to ideas that burned bright and faded.
Why This Port Matters
Port 178 didn't change the Internet. It served a handful of expensive workstations that most people never saw. But it was the window—literally—through which one person saw the future clearly enough to build it.
The Web didn't have to happen on a NeXT Computer. Tim Berners-Lee could have used a different workstation, a different operating system, different tools. But NeXT's environment was good enough, fast enough, that the idea could flow from concept to working prototype in two months.
That matters. How many world-changing ideas died because the tools were too hard to use? How many people saw the future but couldn't build it quickly enough to convince anyone? Port 178 is a reminder that infrastructure matters. The right tools at the right moment can change everything.
Every web page you've ever seen, every hyperlink you've ever clicked, every website you've ever built—all of it traces back to a NeXT Computer at CERN in 1990, showing graphics through port 178 while a physicist wrote code that would connect the world.
The port is empty now. But the window it opened never closed.
Related Ports
- Port 80 — HTTP, the protocol Tim Berners-Lee invented on the same NeXT Computer
- Port 443 — HTTPS, the encrypted version of the Web that succeeded HTTP
- Port 6000-6063 — X Window System, the Unix display server that competed with NextStep's approach
Frequently Asked Questions
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