MindMate is an open-source mind mapping application built with C and the .NET framework, designed to help users visualize, organize, and structure complex ideas through hierarchical diagrams. The software serves as a versatile tool for brainstorming sessions, project planning, note-taking, and knowledge management by allowing users to create nodes, connect concepts, and annotate information intuitively. A standout feature of MindMate is its extensive customization capability, offering 11 built-in visual themes that range from standard light and dark modes to specialized palettes like Solarized, Pitch Black, Fun, and Twine, ensuring a comfortable working environment for different preferences and lighting conditions. Users can further tailor the interface by creating custom themes using the Default Format dialog available in the Format menu. Developed as a free and transparent project, MindMate is available for Windows in both installer and portable versions, making it accessible for immediate use without compl