Can you use Swift for free?

Could you please clarify, is it possible to utilize the Swift programming language without incurring any costs? I understand Swift is a popular choice for developing applications across various platforms, but I'm unsure if its usage comes with any financial obligations. Are there any limitations or restrictions that one should be aware of when considering to work with Swift for free? Additionally, are there any alternative options or open-source tools that might be suitable for those seeking to develop software without incurring expenses?