There are lots of software, this thread is all about open source software that you use daily and believe everybody should use them too.

Let me start the ball rolling,

7-zip ( http://www.7-zip.org )
This is basically my software to zip, unzip and anything else that deal with zip.

Veracrypt ( https://www.veracrypt.fr/en/ )
This is useful in the sense there are secrets which should remain gone forever after you die.

Kingsoft Office ( http://www.kingsoftstore.com/software/kingsoft-office-freeware )
Basically a replacement to Microsoft Office,
rename those self update binary to .bak for block them in firewall

Blender
3D, 2D, animation and etc imagination

Avast antivirus

MPC media player

Adobe Acrobat Reader DC

These are what I usually setup for customer.

WinRAR (endless trial)

SoftMaker Office (80 Mb replacement of office), opens & saves all MS Office formats. it trashes some properties like colorization of cells and VB scripts all rest remain supported.
http://www.softmaker.com

Avast antivirus too.

Tools from sysinternals, MiTeC, nirsoft: especialy HEXEdit.exe (less featured than WinHEX but enought for me) from MiTeC , clipboardic.exe (to see what in clipboard) & openedfilesview.exe (lightweight analog of unlockers) from nirsoft.
http://www.nirsoft.net/
http://technet.microsoft.com/en-us/sysinternals/
http://www.mitec.cz/

WinMerge for file comparison (mostly to compare sources or to find news in manuals)
http://winmerge.org

And for many years I can`t find freeware replacement for cracked IDAPro for reverse enginering... it is sharware, but it partialy opensource(not the program itself, but modules in it) in subfolder ids zipped impoted procnames of every lib(only libs that are part of OS) of every OS for every CPU that IDA supports.in idc subfolder there are sources of file analizer, and in cfg subfolder there are constants for different processor architectures.

what about ollydbg and x86dbg / x64dbg
personally, olly is the best for any 32-bit program.

CFF explorer http://www.ntcore.com/exsuite.php
see everything about your executable module. (.exe, .dll, .sys)

process monitor https://docs.microsoft.com/en-us/sysinternals/downloads/procmon
process explorer https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer
handle https://docs.microsoft.com/en-us/sysinternals/downloads/handle

i like handle, you can watch opened object handles (i.e. process handle, window handle, file handle)

and i have much more utilities, just dont know where are they (probably somewhere on the disk)

I use Winamp v2.9x for 15 years or so.


There is a similar (but much older) conversation here

programs of your daily use

yeah, some of their listed programs (in that post) are installed in my pc too.

i have dup2 (might be no longer available on the web)
its an universal patcher, give it the offset and address and your program will be automatically patched.

any recommendation for no bloat offline open source english (etc translated languages) dictionary with pronunciation?