SyncTeX
SyncTeX is a method that enables synchronization between a TeX source file and the PDF output generated by a TeX/LaTeX compiler. This plugin allows to use SyncTeX in gedit to quickly switch from an opened TeX source file to a PDF document opened in evince and vice versa.
To be useful, this plugin requires a TeX/LaTeX compiler and SyncTeX to be installed. Both are provided by TeX distributions such as TeX Live. Also evince must be installed.
Some basic information on setting up SyncTeX and compiling LaTeX documents can be found in the evince-SyncTeX documentation.
Key shortcuts and mouse controls are also documented in the evince-SyncTeX documentation.
Gnome-LaTeX is an alternative text editor specifically designed for writing TeX code.