Delphi's Palette and What You Could Drop onto a Form

Borland Delphi arrived in February 1995 carrying an idea that Visual Basic had proved commercially: make the user-interface form the centre of the development experience. What Delphi added was a component model with genuine depth. Where Visual Basic bound controls to a runtime interpreter, Delphi compiled everything — the form, its event handlers, the components dropped onto it — into a single native Windows executable. The Visual Component Library, the Object Pascal framework Borland called the VCL, sat underneath all of it, giving every component a class hierarchy a developer could actually read, subclass and extend.

The form designer itself occupied the upper portion of the screen. Below and beside it sat the Object Inspector — a live property grid that updated the moment a control was selected. Change the Width property numerically in the Object Inspector and the component resized on the canvas simultaneously; drag a handle on the canvas and the Object Inspector's field updated in return. The two panes were a single view of the same object state, and that live mirroring made the mid-drag workflow feel qualitatively different from anything available in the same price bracket.

Building software on the hardware where the form designer found its audience.

The component palette ran across the top of the IDE as a tabbed toolbar — Standard, Additional, Data Access, Data Controls, Dialogs, and more. Dropping a TDBGrid onto a form and then dropping a TDataSource and a TTable beside it took perhaps thirty seconds; linking the three through the Object Inspector's dropdown fields wired a live database grid to a Paradox or dBASE table without a line of handwritten SQL. This was the moment developers who had spent years in Clipper or xBase understood what Delphi was for. The database controls were not an afterthought — they were a first-tier feature of the original 1995 release, and they addressed a market Visual Basic served poorly.

The VCL's architecture rewarded expertise. Every visual component descended from TControl; non-visual components — timers, database connections, menu structures — descended from TComponent and appeared on the form's surface at design time as icons that vanished at runtime. A developer building a custom component subclassed the nearest ancestor, overrode the Paint method or the data-aware interface, and installed the result onto the palette. The installed component was indistinguishable from a Borland-supplied one: it serialised to the .dfm form file in the same format, appeared in the Object Inspector with the same property editors, and compiled into the same executable.

The .dfm file — the binary, later text, description of every component's properties and their relationships — was the form's persistent representation. Opening a project compiled the form from that file; saving it serialised the live object graph back. Delphi's compiler, descending from Anders Hejlsberg's Turbo Pascal architecture, was fast enough that a full rebuild of a non-trivial application felt instantaneous on mid-1990s hardware, which kept the edit-compile-run loop short even as projects grew.

Third-party component vendors recognised the market immediately. By 1996 commercial component libraries — grids with cell-level formatting, chart controls, report engines — were available as drop-in palette additions. The extensibility was real because the VCL source code shipped with Delphi Professional and above; a developer encountering unexpected behaviour in a stock component could read the implementation, not just observe it.

This openness, combined with the native-code output and the database-centric palette, defined Delphi's position through the late 1990s. It attracted developers building internal business applications: invoicing systems, warehouse management tools, medical records interfaces — software where a grid that could talk to a database table without ceremony was worth more than a language feature list. Visual Basic's form designer was faster to learn; Delphi's rewarded the developer who stayed longer. The component palette was both the welcome mat and the depth charge.