In addition, it features drag-and-drop support, directory viewing, TWAIN support, slide shows, batch conversion, and modifications such as color depth, crop, blur, and sharpen.
IrfanView is trying to create new and/or interesting features in its own way, unlike some other graphic viewers, whose whole "creativity" is based on feature cloning, stealing of ideas and whole dialogs from ACDSee and/or IrfanView!.

Some Features:
32 and 64 bit version
Many supported file formats
Multi language support
Thumbnail/preview option
Slideshow (save slideshow as EXE/SCR or burn it to CD)
Show EXIF/IPTC/Comment text in Slideshow/Fullscreen etc.
Support for Adobe Photoshop Filters
Drag and drop support
Fast directory view (moving through directory)
Batch conversion (with image processing)
Email option
Multimedia player
Print option
Change color depth
Scan (batch scan) support
Cut/crop
IPTC editing
Effects (Sharpen, Blur, Adobe 8BF, Filter Factory, Filters Unlimited, etc.)
Capturing
Extract icons from EXE/DLL/ICLs
Lossless JPG rotation
Many hotkeys
Many command line options
Many PlugIns
Only one EXE-File, no DLLs, no Shareware messages like "I Agree" or "Evaluation expired"
No registry changes without user action/permission!
and much more

Whats New:
Updated Video PlugIn (improved Win10 compatibility, new player for MP3/FLAC)
Option to play all audio formats in main window (Properties->Video/Sound)
Option to change hotkeys for menus: Right mouse click on menu item
New option in Paint dialog: Fill rect/ellipse with transparent color
New "Edit->Insert Watermark" option: Use color to highlight an area
Option to disable mouse wheel for file browsing (Properties->Browsing)
New SVG PlugIn (Thanks to seppesol)
New XCF PlugIn (Thanks to Jacek SQ6KBQ)
New JPG option: Use QuantSmooth loading (PlugIn, thanks to Ilya Kurdyukov)
Option for page/frame filename suffix in Multipage-Extract dialog
CTRL + "Save-As" icon on toolbar calls the "Save" menu
New option in Advanced batch dialog: Add Border/Frame
New option in Insert Text dialog: Settings for Outline-1 effect (Rainbow)
New paste option: Change paste counter (Edit->Paste special)
New shapes in Hexagon dialog: Ellipse, Cloud; Spiral (thanks to Rod Stephens)
New option in Hexagon/Shadow dialog: Background transparency
Support for PSB format (Photoshop files)
Context menu added to EXIF dialog (Copy only selected lines)
New placeholder: $c (Compression text from Image->Info dialog)
Program icon updated
New Paint dialog icons (Thanks to Michael Grosberg)
CLP format moved to FORMATS PlugIn
JP2 PlugIn loading bugs fixed (thanks to Phung Duc Luan and Linhlhq)
B3D and XCF PlugIn loading bugs fixed (thanks to Zhe Wang)
Formats PlugIn bugs fixed (XPM,XBM,CR2,HDR,WBMB,FITS,DDS) (thanks to nhiephon)
MNG PlugIn loading bug fixed (thanks to zhazha crack)
Several PlugIns are changed/updated, please install the newest versions:

HOMEPAGE