EXHIBIT 99.1
                   HERCULES INVESTS $3 MILLION IN INTERWISE

    PALO ALTO, Calif., Oct. 3 /PRNewswire-FirstCall/ -- Hercules Technology
Growth Capital, Inc. (Nasdaq: HTGC), a leading debt and equity growth capital
provider to technology related companies, today announced that on Sept. 22,
2005 it provided $3 million in financing for Interwise, a privately owned
leader in true enterprise conferencing.

    (Photo:  http://www.newscom.com/cgi-bin/prnh/20050609/SFTH149LOGO )

    "For over 10 years, Interwise has been committed to delivering live
collaboration and e-learning solutions in one comprehensive platform," said
Roy Liu, managing director of Hercules. "Interwise continues to lead the
market in integrated conferencing solutions, and it is recognized for its
leadership in web conferencing and VoIP technology."

    Interwise is the leader in complete enterprise conferencing, and provides
unlimited voice, web and video conferencing in one integrated platform for a
fixed price. Technology Marketing Corporation's TMC Labs division recently
named Interwise's ECP Connect solution as a 2005 Innovation Award winner. The
company's fixed price/unlimited usage business model and enterprise-class
technology combine to make it easy for companies to replace multiple
conferencing and collaboration products with a single, integrated solution
that can reduce overall conferencing expenses by up to 50%.

    About Hercules Technology Growth Capital:

    Founded in December 2003, Hercules Technology Growth Capital, Inc. is a
NASDAQ traded specialized finance company providing debt and equity growth
capital to technology related companies at all stages of development. The
company primarily finances privately held companies backed by leading venture
capital and private equity firms and also may finance certain publicly traded
companies. Hercules focuses its investments in companies active in technology
and technology related industries such as computer software and hardware,
networking systems, semiconductors, semiconductor capital equipment,
information technology infrastructure, Internet consumer and business
services, telecommunications, and life sciences. The company's investments are
originated through its principal office located in the Silicon Valley, as well
as additional offices in the Boston, Boulder and Chicago areas. Providing
capital to privately held companies backed by leading venture capital and
private equity firms involves a certain degree of credit risk and may result
in potential losses.

    For more information, please visit http://www.herculestech.com . Companies
interested in learning more about financing opportunities should contact
info@herculestech.com or call 650-289-3060.

    About Interwise:

    Since 1994, Interwise has been committed to delivering live collaboration
and e-learning solutions in one comprehensive platform. Recognized for its
leadership in web conferencing and VoIP technology, Interwise continues to
lead the market in integrated conferencing solutions.

    Long before the company's first product shipped to customers in early
1997, the Interwise team strenuously applied a live-event, user-centric focus
to the company's market and technology vision, targeted business strategies
and project execution. The result is Interwise's globally acclaimed industry
leadership and consistently first-to-market innovations for live online
interaction, collaboration and learning.

SOURCE  Hercules Technology Growth Capital, Inc.
    -0-                             10/03/2005
    /CONTACT:  Deborah Stapleton, +1-650-470-0200, for Hercules Technology
Growth Capital, Inc.; or Hercules Technology Growth Capital, Inc.,
+1-650-289-3060, or info@herculestech.com/
    /Photo:  http://www.newscom.com/cgi-bin/prnh/20050609/SFTH149LOGO
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    /Web site:  http://www.herculestech.com/
    (HTGC)