As described in getting started page, at the minimum, writing and running Tyl code, can be done by coding in a simple text editor, and running from file manager. But if the program is more complicated or raises an "unexplained" errors, it is needed to use IDE tools and debugging technics to handle coding efficiently.

The minimum requirements from an IDE tool are:
Details about various IDE tools in the market and their abilities and qualities are beyond the scope of this guide, so as to describe the coding posibility, let's focus on Microsoft Visual Studio ™ (will be abbreviated to VS).
This guide is by no means a comprehensive guide on VS, and the programmer that's not familiar with VS, should do it by checking VS website and other sources. But to help with coding in VS, and also for totally novice audience, or even for experienced programmers that are not familiar with these posibilities, a detaild instruction from scratch is provided here.
Project Setup & Running
download VS and install it on your computer
create on your file system, for ex. at 'C:\' root, a directory 'tylprojects'
open VS, and choose 'Create a new project'
in templates text box write 'library framework'
'Class Library (.NET Framework)' will pop to first option
choose it and 'Next'

under 'Project name' write 'taskmanager'
under 'Location', browse to and select 'C:\tylprojects'
tick the 'Place solution and project in the same directory'
in Framework dropdownlist, select '.NET Framework 4'
and 'Create'

in 'Solution Explorer', the new project is open with a first file 'Class1.cs'
click on the file 'Class1.cs' to mark it
load 'Properties' window (ALTENTER)
in 'File Name' write 'taskmanager.tyl'
in 'Copy to Output Directory' select 'Copy if newer'
the file renamed, and the contents can be cleared

in 'Solution Explorer', click on the project name to mark it
load 'Properties' window (ALTENTER)
from left side select 'Build'
in 'Output path', clear the text box
from left side select 'Debug'
in 'Debug' window, select 'Start External Program'
browse your file system in search for Tyl installation directory
usually at C:\Program Files\Tyl Software Foundation\Tyl Software
select 'TylLauncher.exe'
in 'Command line arguments' text box, write 'taskmanager.tyl'
save all changes

a starter code for task manager is found here
copy it to 'taskmanager.tyl' file
press on 'Start' to run Tyl program

you should see that VS is in debug mode, and Tyl Launcher is running with the results in the run box: