Synapse is NOT a set of components. It is only library of units with code and classes. It cannot be installed, it does not need to be installed! To use Synapse, you simply copy all the necessary Synapse units to your project directory (or to your library search path) and in your project add a USES line listing the needed Synapse units.
If you would like to configure your Lazarus IDE to be ready to use Synapse with all of your projects without having to copy the units to every single one of your project directories, then do this (Note: this was tested on Lazarus v0.9.12 BETA other versions are subject to change): First copy Synapse to any folder you wish (I have it in the components folder of Lazarus, but you can put it anywhere you like) then in the menu go to “Environment>CodeTools options” (Note: > means sub-menu). Then a small window will popup, when that happens there should be a textbox at the top that says “Aditional source search path for all projects” or something similiar to that. What you must do is insert the directory in which you have copied Synapse to. And there you have it. You are done. Enjoy using Synapse!
The non-component concept is very good for writing non-visual applications, i.e. Windows services, CGI programs, Command-line programs. You may use Synapse in a visual program too. It is easy!
TCP/IP communication cannot be visualised, so why use visual components?
Here's how to add Synapse to Delphi (7; It might be different in more recent versions of the IDE):