Lawena
Lawena Recording Tool is a cross-platform tool coded in Java, originally developed by Montz and now maintained by Quantic, it provides a flexible user interface for the recording of image sequences from TF2. Lawena is considered the spiritual successor to the PLDX tool who was one of the first and the most popular tool used for recording tf2 videos before it was discontinued.
The tool allows through it's interface and settings the recording of clips from demos with ease, making it an essential tool for the tf2 competitive community. It has been used in numerous videos and many of the most famous fragmovies used this or a similar tool to record clips from demos.
Interface
Since everything lawena does can be done within the game with no external tools the interface here is the key factor which makes a tool of this kind a much more efficient option.