Windows and the Enterprise Software Era

To understand why C# exists, you have to understand the world C# was born into. By the late 1990s, Microsoft was not just a software company. It was, by an enormous margin, the dominant platform for business computing on the planet.

This page is a quick tour of that world. We won't run any C# code here — just lay down the historical scaffolding you'll need for the rest of the story.

From a startup to a platform

Microsoft began in 1975 as a small company writing programming language tools. Its first major product was a BASIC interpreter for the Altair 8800 — a hobbyist computer. The company's big break came in 1981, when IBM chose Microsoft's MS-DOS as the operating system for its new IBM PC.

By 1995, Windows 95 made graphical computing mainstream. By the late 1990s, the vast majority of office computers in the world ran Windows, Microsoft Office, and Internet Explorer. Microsoft wasn't just a vendor — it was the substrate most business software ran on.

What "enterprise software" actually means

"Enterprise software" is a vague phrase, but it has a concrete meaning. It is the unglamorous code that runs the business world:

• Accounting and payroll systems. Every paycheck issued in a Fortune 500 company.
• Inventory and supply chain systems. What's in the warehouse, what was shipped, what needs reordering.
• Customer relationship management (CRM). Who your customers are, what they bought, when to call them.
• Internal line-of-business tools. The form a bank teller fills in when you open an account; the screen a hospital nurse uses to enter a patient's vitals.

This software has unglamorous but ferocious requirements:

These requirements explain almost every decision .NET and C# would later make.

The Microsoft developer toolchain before .NET

By the late 1990s, Microsoft offered three major tools for building software on Windows:

Each tool had real strengths and real weaknesses:

• Visual C++ gave you raw, fast access to Windows. But C++ is notoriously unsafe: pointer bugs, memory leaks, and crashes were daily companions. Productivity was low. Hiring junior developers who could be trusted with C++ was hard.
• Visual Basic was the opposite — it made it astonishingly easy to drag a button onto a form and write a few lines to make it work. But it was not really suitable for large, complex systems.
• Visual J++ was Microsoft's version of Java. It had the safety developers wanted, but it became the center of a huge legal and technical fight with Sun Microsystems (the owner of Java), which we'll get to in the next chapter.

What was missing was a single language that was as safe as Java, as productive as Visual Basic, and as powerful as C++ — and that was deeply integrated with Windows.

COM, ActiveX, and the integration headache

A second problem was that Windows applications needed to talk to each other — Excel embedding a chart from another tool, a Word document calling out to a custom plugin, a banking app driving a spreadsheet. Microsoft's answer was a technology called COM (the Component Object Model), later extended as ActiveX.

COM worked. It was used everywhere. But it was also famously brittle:

• Registering and unregistering components in the Windows registry.
• Cryptic error codes like HRESULT 0x80004005.
• Each language (C++, VB, J++) had a completely different way of using COM.

Senior engineers at Microsoft increasingly believed that the next big platform needed to fix all of this at once: safety, productivity, integration, and language interoperability.

What a "platform" really is

Before we move on, it's worth pausing on the word platform, because it will come up constantly.

A platform is everything underneath your application that you don't have to write yourself: the operating system, the runtime, the standard library, the file system, the network stack, the GUI framework. The job of a great platform is to make the things you do write feel small and focused.

By the year 2000, Microsoft was preparing to bet the company on a new platform that would unify its languages, fix the safety problems of C++, integrate cleanly across applications, and (it was hoped) win the next decade of computing.

That platform would be called .NET, and its flagship language would be C#.

But before we get there, we have one more thread to weave in: the language that frightened Microsoft enough to motivate all of this in the first place — Java.

Test your understanding

QuestionSelect one

Which of these is the best description of "enterprise software"?

Software written only by very large companies

Games and consumer apps

Long-lived business software (payroll, CRM, inventory, line-of-business tools) with strong requirements around reliability, integration, and maintainability

Software written exclusively in C#

QuestionSelect one

What was the main gap in Microsoft's developer toolchain in the late 1990s?

Microsoft had no programming languages of its own

Windows wasn't popular enough to write software for

There was no single language that combined safety, productivity, and power, with deep Windows integration

C++ wasn't installed on enough machines