[atjnjk]

Originally Posted by itimpi

The other point to remeber is that basically the Calibre viewer is an ePub viewer.

AFAIK, epub, mobi and other html based formats are the ones that work best with calibre viewer (fast, extremly customizable with CSS, reopening last page read). If you want to read rtf, try AlReader (scroll down, the download link for english windows version is on the buttom right, or you could use google translate). If you have more questions about this software, please create a new thread here and point me there as this is not related to calibre.
Some rough translated information:

Spoiler:

more english info: http://reeed.ru/en_prog_alreader_win.php
info [russian]: http://reeed.ru/prog_alreader_win.php
help [russian]: http://reeed.ru/prog_alreader_help.php

# rotate the screen 90 °, 180 °, 270 °
# Profiles «Day» / «Night» (in the profile includes settings of text font: size, Bold, smoothing, color: the background, text, and the status bar) - up to 8 profiles
# Read HTML, FB2, EPUB - support text styles, images, referrals, content.
# Reading CHM - experimental support.
# Read TXT, RTF, PDB / PRC (PalmDOC, zTXT mode 1), TCR files, DOC, DOCX, ODT, SXW, ABW, ZABW - text only.
# Read from ZIP archives and GZ.
# Read the archives RAR (required unrar.dll, which currently is only for Win2000, WinXP, Vista)
# JPG, PNG, GIF, BMP. EMF and WMF formats are supported only for Win2000, XP, Vista
# Any choice of encoding
# Proper translations for 23 languages ​​(templates TeX)
# Normal full-screen mode (no top line)
# Status bar (time, battery, percentage and number of pages read). Visibility status bar is configured separately for full-screen mode and normal
# Line position in the text (bottom, right or in the status bar). Visibility is configured separately for full-screen mode and normal
# Display the battery status on the line of the text
# Joystick buttons are rearranged along with the rotation of the screen
# Interline adjustment and character spacing [change space between lines and characters]
# Alignment on width [width adjustment]
# List of recent open books[List of last opened books]
# ClearType font
# Several types of Autoscroll (wave, small wave and smooth)
# Bookmarks with navigation on them
# Global bookmarks with navigation on them
# Configuring hardware buttons taps and strokes on the screen
# Search for any text string + using the search bar with symbol «?», which is interpreted as any one character.[Search for any text string, excluding the number of spaces and line breaks between words + using the search string character "?" which is interpreted as one character. Search регистронечуствителен.]
# Jump to text (percent and pages)
# Preservation of quotations [Saving quotes]
# Save readable file as TXT, PDB or HTML.
# Screen highlighting [backlight can be left on]
# test support for the librarian
# footnote at the bottom of the page
# edit typos in fb2 straight while reading
# Work with built-in dictionary and dictionary Dict, Lingvo and Slovoed [Work with dictionaries: Dict, Lingvo and Slovoed]

Supported OS: Windows Mobile 2003, Windows Mobile 2003 SE, Windows Mobile 5, Windows Mobile 6 Standard, Windows Mobile 6 Classic, Windows Mobile 6 Professional, Phone Edition, WM VGA 480x640, Real VGA, WM 240x240, WM 480x480, MS Smartphone 2002, MS Smartphone 2003, WM Smartphone 2003 SE, WM Smartphone 5, WM Smartphone 240x320, Win 2000, Win XP, Win 7