Any search engine results may give you dozens of free software alternatives to use on your given choice of computer platform. Here are some open-source packages that can work for all models.
Audacity is the most robust recorder and sound editor in the FOSS (Free and Open Source Software) world. It is also the easiest to use, with the fastest learning curve. Its only drawback is that you cannot “scrub” audio – which is the process of playing a file back very slowly by dragging the mouse over the audio region on screen. Scrubbing is very useful for dialogue, as explained later.
Ardour is a DAW software. It is sophisticated, which means a steeper learning curve, but more functionality. Ardour also lets you scrub audio, which is a huge advantage. Ardour has done quite a bit to compete in the level of Pro-Tools, which is the industry-standard for-pay software.
Although harder to use than Audacity, Traverso has a few useful functions, such as the ability to scrub audio. Designed to replace expensive DAWs (Digital Audio Workstations), Traverso has many features only high-end software can give you.