Yes these are all three Build tools.
Question is what do you want to build and what about deployment?
Next question: build tool is one thing, but how much are you willing to spend on (internal or external) services to get your build tool up and running and to get the build tool to do what you want.
Or do you want an out-of-the-box build (and deploy) solution that is up and running in no time?
I had a nice discussion with a manager of a consultancy company about open source versus commercial software. He liked open source as people can spend the money only once: or expensive software or open source and spent money on implementation. I honestly don't follow him completely, but he has a point. Consultants earn a lot of money where some tasks (like WebSphere CI and CD) can be done out-of-the-box at finally lower cost.
Our IKANALM solution can be used for some out-of-the-box implementations like IBM z/OS, SAP and Websphere.
René De Vleeschauwer
Jenkins is almost a de-facto standard.
It's simple to deploy and use, has a huge community and lots of plugins... and is free (MIT license).
The main advantage I see in the other two options you mention is they're better suited for distributed tasks and so they'll probably scale up better.
Additionally they're more modern and less boring than Jenkins (well, this is a little bit subjective but Jenkins is and old-fashioned monster with all its pros and cons).
In my opinion, unless you are dealing with really huge environments, Jenkins will be much easier (and cheaper) to start with and will probably cover all your needs.