The requirements for Snipe-IT are fairly standard for a modern web server, and most servers will have most or all of these components already installed. If for some reason you don't have them installed, they are relatively easy to add.
NOTE ON SHARED HOSTING:
If you're installing Snipe-IT on shared hosting, you should have most of these installed already, with the exception of LDAP. LDAP integration may not be possible on shared hosting, depending on your web host. Email your hosting provider's support team to determine if your server meets the requirements to install Snipe-IT.
PHP >= 5.6.4
PHP Extensions:
MySQL or MariaDB
GD Library (>=2.0) or Imagick PHP extension (>=6.3.8)
For barcode generation and image resting for image uploads.
Atom.io, Notepad++ or another plain-text editor for the editing configuration file
The specific text editor doesn't matter, just as long as it doesn't save as rich text or try to convert apostrophes and quotes into curly quotes.
Git
Recommended for easier install/upgrade, but not required.
Mod Rewrite
SSH access to the server w/an SSH client (like Terminal.app for OSX Desktops or Putty for Windows Desktops)
IIS
IIS URL Rewrite
MariaDB 10.0.14 for Windows
PHP Manager for IIS (makes managing PHP on IIS much easier)
Notepad++ for editing files