ShareX is an open source screen capture tool with a very extensive feature list.
The program doesn't just grab individual windows and a full screen, for example. You can also capture rectangles, ellipses, triangles, diamonds, polygons or freehand shapes. There's support for multi-monitor systems, and even a screen capture tool to save desktop activity as an AVI or animated GIF.
Any image you might grab can be processed in many ways. You can crop, resize or rotate it; annotate it with lines, arrows, shapes, textboxes and more; obscure confidential details (passwords, say) with the obfuscator; customise it with a watermark, or apply special effects, including borders, shadows, torn edges and more.
Once you're happy, ShareX can directly upload your work to more than 30 online services, including Twitter, Flickr, Picasa, Photobucket, Dropbox, OneDrive, RapidShare and GoogleDrive. You get a module to create custom uploaders for sites which aren't in the list. And there are also more general options, like the ability to send a grab via email, or copy it to a shared folder.
Even now, the program hasn't finished. Once the capture has been uploaded, you can have ShareX do something with the link: use your preferred URL shortening service, post it on Twitter, send it in an email, maybe just paste it to the clipboard.
Best of all, this is extremely configurable. You might set your preferred file format, set up the effects you'd like to apply, define a precise format for the saved file name, launch a custom program to work on it, select multiple upload destinations (you're not restricted to just one) and more, then launch the entire process with a custom hotkey.
Version 10.4.0 brings (changelog):
•Added Seafile file uploader (by @zikeji)
•Added support for Pomf file uploader clones with 17 clones predefined and ability to setup your own (default is pomf.cat)
•Added Uguu file uploader
•Updated Lambda API and added result link options (by @mstojcevich)
•Added file name field to "Post capture tasks" window
•Added rectangle drawing support to Region (Annotate) (it has 3 modes now: Capture, Rectangle drawing, Pen drawing)
•Improvements in UI and hotkey tips for Region (Annotate)
•Added auto upload, auto close, scroll to top method options for Scrolling capture
•Separated Scrolling capture window -> Capture tab to 3 groups (Before capture, While capturing, After capture) for it to be more easily understandable
•Added headers support and location header response option to custom uploaders
•Added show most recent link first setting
•Added warning icons for unsupported WebM audio codecs and slow x264 presets
•Added debug menu to tray menu
•Having empty file with the file name Portable in the same folder as ShareX.exe will make ShareX portable
•In portable mode, ShareX auto updater will open download URL of portable ShareX version in browser
•Added Show "Upload with ShareX" button in Windows Explorer context menu option to ShareX setup
•When hotkeys are disabled all hotkeys except "Enable/Disable hotkeys" hotkey will be unregistered (by @mpistrich)
•If saving image fails during an after capture task "Save image to file as...", then save dialog will reopen (by @mpistrich)
•Added area info for cursor hover area in "Region (Windows & controls)" mode
•In default clipboard image copy, background will be filled with white because alpha channel is not supported
•Logs will save instantly in separate thread now instead of waiting for ShareX to close
•Show the application name that could cause the hotkey conflict when ShareX fails to register hotkeys