base-tclsvc-thread

This executable basekit is provided in some ActiveState ActiveTcl distributions.

TWu 2025-01-27 - It is provided by the Tcl Dev Kit for services on Windows systems.
I used this feature over years properly.
The online help file states (cited from version 5.4.1):

Service Manager

• Renamed Executable: To start the Service Manager from the Windows command line, enter tclsvc.tcl.
• Service Base Kit: The Tcl Dev Kit includes a new base kit ("base-tclsvc-win32-ix86.exe") that can be used to build "portable" services.
  When using TclApp to generate the application, specify base-tclsvc-win32-ix86.exe as the prefix file.
  This service can then be installed on any system (using the Tcl Dev Kit's Service Manager) that supports Windows NT-based services.

Windows Services are applications that run in the background on Windows systems. These applications have no user interface, as they are designed to run with no user intervention. Sometimes a service has an administrative tool for configuration and interaction; however, the service itself runs independently.

Services are usually automatically loaded whenever the system boots. They run outside of the context of the user (if any) who is currently logged in on the system. Therefore, the service's privileges are separate from the user login, and are tied to the service itself, not the user who launches the service.

The TclApp component of the Tcl Dev Kit is used to create Tcl applications that will be deployed as services. ... The Tcl Dev Kit includes a base kit (Tcl/bin/base-tclsvc*) for creating portable services.

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