Scite

Scite is a flexible instrument that can be used for a wide range of needs, is free of cost, and allows its users to customize their working environment with ease.

Scite is a free and powerful code and text editor that lets you perform advanced searches, configure your code/text editing panels, use syntax highlighting, and much more.

The free application is also extremely small in size and does not require installation. As such, only by unzipping the app's directory, you can interact with an environment that is completely self-contained and has all the prerequisites and dependencies already set in place.

Also, the editor has support for a lot of well- and less-known programming and scripting languages, including Perl, Ada, C-like languages, Pascal, Python, Java, PHP, Fortran, Mathlab, TeX, SQL, Shell, etc.

The app has a simplistic interface with on-point commands, and it's also suitable for users who like to customize their setups. When it comes to how you choose to format your content, you have a wide variety of options. You can complete symbols, copy text as RTF to the clipboard for handling your content cross-platform, choose your encoding type (between page's proprietary instance, UTF-8, or UTF-16), or export content in PDF, LaTeX, HTML, RTF, and XML, and much more.

Regarding the program's search function, you have the option to search in one file or across multiple other ones, perform incremental searches, as well as manage bookmarks, navigate content based on bookmarks, and others.

Plus, you can add box comments, make your selections lower or upper case, reverse selected lines, join or split paragraphs, insert and expand abbreviations, replace strings/text portions in opened buffers, etc.

To summarize, Scite is extremely customizable and versatile. You can easily integrate it into your environment and create user-defined functionality or edit existing defaults. With all its available options, the tool can be used as a text editor, code writing panel, for academic purposes, and others.