Many teams acquire the source code after using the compiled DLL for years. Here is what you must check:
is a comprehensive components library for Windows Forms (WinForms) that allows developers to create professional user interfaces with ease. Before Microsoft modernized its own UI toolkits, DotNetBar provided the "Office-style" ribbon bars, dockable windows, and advanced tree views that were otherwise impossible to build from scratch in standard Visual Studio environments.
– Maintaining a legacy million-line WinForms app that cannot be rewritten. For you, yes. The source code is a lifeline. It allows bug fixes, minor enhancements, and peace of mind.