Probably the MS Office Suite is the only product of Microsoft that has no competitor threatening its stranglehold of the world in near future. The integrated applications of the Office suite such as word processing, spreadsheets, presentations, and database management are the industry standards that others are trying to copy. However, not all small businesses have enough resources to buy MS Office licenses for their employees. Therefore, it is important to know that what alternatives are there for these small businesses in a free and open-source world. Here we have compiled a list of the top 5 open source Office suites that can be the best alternatives to MS Office suites. And we believe, one of these might come up to be a real competitor of MS Office not just in terms of features but in terms of value to the people.

1. LibreOffice

Although LibreOffice was forked from OpenOffice.org in 2010 as a free and open-source clone, in terms of features and productivity it has overtaken OpenOffice. LibreOffice, developed by Document Foundation, comprises word processing, spreadsheets, presentations, diagrams, and database management.

Applications

LibreOffice Writer - A word processor with similar functionality and file support to Microsoft Word with WYSIWYG features as well as basic text editor capabilities.
LibreOffice Calc - A spreadsheet program, similar to Microsoft Excel.
LibreOffice Impress - A presentation program resembling Microsoft PowerPoint. Presentations can be exported as SWF files to view as flash presentations.
LibreOffice Draw - A vector graphics editor and diagramming tool similar to Microsoft Visio and comparable in features to early versions of CorelDRAW.
LibreOffice Math - An application designed for creating and editing mathematical formulae. These formulas can be incorporated into other documents such as those created by Writer or Calc.
LibreOffice Base - A database management program, similar to Microsoft Access.

2. OpenOffice

Apache OpenOffice is also a free and open-source office suite. It could be viewed as a close cousin of LibreOffice and NeoOffice. Similar to other office suites, it also contains a word processor (Writer), a spreadsheet (Calc), a presentation application (Impress), a drawing application (Draw), a formula editor (Math), and database management application (Base).

Applications

OpenOffice Writer - A word processor analogous to Microsoft Word.
OpenOffice Calc - A spreadsheet analogous to Microsoft Excel.
OpenOffice Impress - A presentation program analogous to Microsoft PowerPoint. It can also export presentations to Adobe Flash (SWF) files.
OpenOffice Draw - A vector graphics editor comparable in features to the drawing functions in Microsoft Office.
OpenOffice Math - A tool for creating and editing mathematical formulae. Formulae can be embedded inside other OpenOffice documents such as those created by Writer.
OpenOffice Base - A database management program analogous to Microsoft Access.

3. NeoOffice

NeoOffice is an office suite for the Max OS operating system. It is also a fork of free and open-source OpenOffice.org just like LibreOffice. It also implements all of the features for Mac OS X which includes word processor, spreadsheet, presentation program, and graphics program.

Applications

NeoOffice Text - Similar to Microsoft Word. It supports many document formats including MS Word (.doc) format. It's own support formats are NeoOffice 1.0 Text Document (.sxw) and NeoOffice 1.0 Text Document Template (.stw).
NeoOffice Spreadsheet - Similar to Microsoft Excel. Its supported document formats are NeoOffice 1.0 Spreadsheet (.sxc) and
NeoOffice 1.0 Spreadsheet Template (.stc) along with other formats including MS Excel format (Xls).
NeoOffice Presentation - Similar to Microsoft PowerPoint. It's supported document formats are NeoOffice 1.0 Presentation (.sxi) and NeoOffice 1.0 Presentation Template (.sti) along with other formats including MS PowerPoint format (ppt).
NeoOffice Drawing - A vector graphics editor comparable in features to the drawing functions in Microsoft Office.
NeoOffice Formula - A tool for creating and editing mathematical formulae.

4. KOffice

KOffice is a free and open-source office suite and graphics suite by KDE for Unix-like systems and Windows. KOffice contains a word processor (KWord), a spreadsheet (KSpread), a presentation program (KPresenter), and a number of other components that varied over the course of KOffice’s development. However, the main website of KOffice went offline in 2012 due to conflicts with their team that parted their way and came up with the Calligra Office Suite.

Applications

KWord Application - A word processor with style sheets and frame-support for DTP-style editing of complex layouts.
KSpread Application - A spreadsheet application with multiple sheet support, templates, and more than 100 mathematical formulae.
KPresenter Application - A presentation program with image and effect support.
Kivio Application - A programmable flowchart drawing program with dynamically loadable stencils. Developed by the company, which offered additional (non-free) stencils for sale.
Karbon - A vector drawing application with a variety of drawing and editing tools – formerly known as Kontour and illustrator.
KChart Application - Integrated report and chart generators.
formula Application - An integrated mathematical formula editor.
Plato Application - A project management application that can create Gantt-style charts.

5. CalligraOffice

CalligraOffice Suite is a graphic art and office suite by KDE forked from KOffice in 2010. It contains applications for word processing, spreadsheets, presentation, databases, vector graphics, and digital painting. Calligra Suite has more bundled applications than any other open-source office suite. Its user interface is also very appealing as compared to other open-source office suites. However, it has very limited support to convert its document to other formats.

Applications

Calligra Words - A word processor with the ability to import Microsoft Word documents.
Calligra Sheets - A spreadsheet program, formerly known as KSpread and Calligra Tables.
Calligra Stage - A presentation program, formerly known as KPresenter.
Calligra Kexi - A visual database management front-end, similar to Microsoft Access.
Calligra Plan - A project management application that can create Gantt charts. Formerly known as KPlato.
Calligra Braindump - A notetaking and mind mapping application.
Calligra Flow - A flowchart drawing program with dynamically loadable stencils. Formerly known as Kivio.
Calligra Karbon - A vector graphics editor, formerly known as Karbon.
Calligra Krita - A digital painting program with some image editing features. Formerly known as Krayon and KImageshop.
Calligra Author - An e-book authoring application like iBooks Author with EPUB export.