MsgBox

Oriented toward software developers, MsgBox is a small-sized tool that gives you the possibility to implement standard popup messages into your applications, which are supported by MessageBox API.

Design modal dialog boxes using MessageBox API

The MessageBox function of Windows is responsible for displaying modal dialog boxes with system icons, various buttons and descriptions, like status or error details.
MsgBox can be accessed from Command Prompt or another console-based environment you prefer. Double-clicking the executable file brings up a graphical window with the usage syntax, so it's necessary to call the process from a command-line window.

Use Command Prompt to easily edit boxes

The syntax is MsbBox.exe MessageToDisplay [/c:Caption [/t:Type] [/? | /h], where /? or /h can be used for refreshing your memory when it comes to this syntax.
Therefore, you have to specify the message that will be shown in the popup window (MessageToDisplay), the dialog box title (/c:Caption, default title is "Error") as well as the contents and behavior of the dialog box (/t:Type).

Integrate buttons, icons and behavioral components

When it comes to the type, it's possible to display buttons, such as "Abort", "Retry" and "Ignore" (MB_ABORTRETRYIGNORE), "Cancel", "Try Again" and "Continue" (MB_CANCELTRYCONTINUE), "Ok" and "Cancel" (MB_OKCANCEL), or "Yes", "No" and "Cancel" *(MB_YESNOCANCEL), among other options.
Otherwise, you can display icons, like yellow exclamation point in a triangle (MB_ICONEXCLAMATION), the lowercase i inside a blue circle for information (MB_ICONINFORMATION), red stop sign in a circle (MB_ICONSTOP), and others. After hitting the Enter key, the message instantly pops up on the screen for your preview.

Simple MessageBox designer that uses CMD

To sum it up, MsgBox offers a simple solution for helping you design modal dialog boxes using the Windows MessageBox API via the command-line interface. However, it doesn't include documentation with all MessageBox commands.