1. Install Tcl.
2. Install git.
3. Set the TCLLIBPATH environment variable. This is where Tin will be installed and where packages installed by Tin will be located.
   • Note: The environment variable TCLLIBPATH must be formatted as a Tcl list, and forward slashes must be used for folder separation, regardless of platform. For example, on Windows, if the folder you want to install Tcl packages to is "C:\Users\username\Tcl Packages", the environment variable should be set to "{C:/Users/username/Tcl Packages}". If TCLLIBPATH is not set to a writable path, Tin will search the Tcl "auto_path" list to find a writable path. If none is found, installation will fail.
4. Download the latest release of Tin and extract the source files.
5. Run the "InstallTin.bat" file (Windows), or run "install.tcl" in a Tcl interpreter.

Once Tin is installed, upgrading Tin is easy! Just copy the code below into a Tcl interpreter.

package require tin
tin autoadd tin https://github.com/ambaker1/Tin install.tcl
tin upgrade tin

To install a package with Tin, there must be a unique repository-tag-file installation path for that version. For example, as shown below, the package "foo" version 1.0 can be installed by running the "install_foo.tcl" file in the repository "https://github.com/username/foo" with release tag "v1.0".

package require tin
tin add foo 1.0 https://github.com/username/foo v1.0 install_foo.tcl
tin install foo

If you are developing your package to be compatible with Tin, there must be a Tcl file in your repository that can be run to install the package. Here is a simple example of an installation file that just copies specific files to a library directory:

# Install dependency
package require tin
tin add bar 1.2 https://github.com/username/bar v1.2 install_bar.tcl
tin depend bar 1.2

# Copy files over to library folder
set dir [tin mkdir -force foo 1.0]
file copy README.md LICENSE foo.tcl pkgIndex.tcl $dir

If your package has binary release files on GitHub, such as .exe installers or .zip archives, the installation file can be modified as shown below, using GitHub CLI to download the release assets.

# Install dependency
package require tin
tin add bar 1.2 https://github.com/username/bar v1.2 install_bar.tcl
tin depend bar 1.2

# Use GitHub CLI to download release assets (InstallFoo1.0.exe and foo1.0.zip)
exec gh release download v1.0 --clobber; # --clobber overwrites

# Customize installation for operating system
switch -- $::tcl_platform(os) {
    Windows {
        # Run binary installation file
        exec InstallFoo1.0.exe
    }
    default {
        # Extract zip folder, and install contents to library folder
        package require zipfile::decode 0.7.1
        ::zipfile::decode::unzipfile foo1.0.zip [pwd]
        set dir [tin mkdir -force foo 1.0]
        set files [glob -directory foo1.0 *]
        file copy {*}$files $dir
    }
}

Full documentation here.