I've used LibreOffice as my main office suite since it forked from OpenOffice five years ago. Now its latest edition, LibreOffice 5.0, is better than ever. And, in my book, that means it's the best standalone office suite available in 2015.
While LibreOffice 5.0 won't be officially released until August 5, the program is already available to install. You can run it today on Red Hat and Debian-based Linux distributions, Mac OS X 10.8 (Mountain Lion) or higher, or Windows Vista or better. Note: The 64-bit edition will not run on Windows XP, but the 32-bit version will run on XP.
One quirk about installing LibreOffice is that you have to download and install the help files separately. While annoying, adding the help file is trivial.
Once the full package is up and running, you'll find that LibreOffice is much faster now than it was in earlier editions. There's been no single reason for this speed increase. I just know that on both Linux Mint 17.2 and Windows 7, LibreOffice 5 runs more smoothly than it has before.
If you're looking for something fancy and new in the user interface, you aren't going to find it. This version, just like the earlier ones, looks more like MS-Office 2003 than anything more up-to-date. That's just fine.
I've always preferred the classic windows, icon, menu, and pointer (WIMP) interface over MS-Office's ribbon interface. The only change that LibreOffice has made to its interface in recent years was the addition of an IBM's Lotus Symphony style sidebar menu. If, like me, you want to produce words, spreadsheets or presentations and not worry about using a new interface, you'll like LibreOffice 5.
LibreOffice's real virtues lies under its plain, old-fashioned interface. Here you'll find numerous small but significant improvements.
For example, LibreOffice does a better job than ever of supporting Microsoft's default Open Office XML (OOXML) format. Since you're always going to have co-workers who are using MS-Office, this is a vital feature. For example, it may seem minor but being able to preserve both highlighting and shading while importing and exporting Microsoft Word documents can save you some major headaches.
Calc, LibreOffice's answer to Excel, has also been improved. That said, if you have very complex Excel spreadsheets, I still can't recommend using Calc as a drop-in Excel replacement.
Don't get me wrong, Calc is a very good spreadsheet program. The problem is it's still not 100 percent compatible with Excel's formulas. Still, its Excel compatibility is better than it used to be. For instance, table-structured references in spreadsheet formula expressions can now be successfully imported from OOXML spreadsheets.
Another nice overall improvement is that you'll no longer need to import user profiles from an older version of LibreOffice to this one. The user profile stays in in the same location as your previous version of LibreOffice. So, for example, on Windows, if your user profile is in C:\Users\<username>\AppData\Roaming\LibreOffice\4\user or on Linux, /home/<username>/.config/libreoffice/4/user, the profile will stay there and be used by your new installation. This means that you won't need to import your customized spelling dictionary.
Last, but not least, LibreOffice still won't cost you a dime. Now, if you want the project to keep going I urge you to donate to LibreOffice's parent organization, The Document Foundation. But, that's optional. If your IT budget is tight, or you don't want to be tied to a proprietary software vendor, you can't beat LibreOffice.